Off the bat, IAABNQAL (I am almost but not quite a lawyer, took the bar but no results until Oct.) so take this with as many grains of salt as you feel appropriate. This isn't legal advice, etc etc.
The short answer is, this is pretty much unsettled law, but there is good reason to believe that the knowledge and status of the caller (i.e. business vs individual)
would matter. The Wiki article cites
Kearney v. Salomon Smith Barney Inc., 39 Cal. 4th 95 (2006) for the proposition that, at least if one caller is in CA, its stricter two-party law still applies to out-of-state callers trying to (legally, in their own jurisdictions) record phone calls with CA residents. However, that is too broad a generalization.
The defendant in that case was Smith Barney, a national brokerage (corporation) with independently sufficient contacts for CA to exercise
personal jurisdiction over it anyway ("SSB 'systematically and continually does business' in California, and SSB does not deny that it maintains numerous offices and does extensive business in this state"). SSB was conversing with
clients in CA (two-party), but making and receiving calls in GA (one-party), and the CA Supreme Court found that there were compelling reasons not to let a company doing business in CA escape the CA privacy law, much less a business with offices in CA that could conveniently "outsource" its calls to other states (pretty much gutting the law). On a technical point of law, this was also a ruling reversing the trial court's dismissal of plaintiff's case, merely allowing the case to proceed and not addressing many of SSB's factual arguments (like "hey, this isn't what the legislature meant by 'confidential communication'").
However, look at it from the out-of-state consumer perspective and everything changes. Lets make the easy assumption that you don't have any presence, property, or business dealings in the two-party state of CA. First, from a personal jurisdiction standpoint, if someone from an unknown location (oops it's CA, gotcha!) is calling you in your one-party state, you have not established
minimum contacts with California because you did not
purposefully avail yourself of CA's laws—you didn't contact CA on purpose!
What if you know they're calling from CA? You're hardly directing any activity at CA by answering the phone. What if you're the one making the call and it's an 800 number to a destination unknown? This happens all the time, on the same day I'll make three calls to customer service and get centers in Illinois, Arkansas, and Pennsylvania. Well, you still haven't directed your action at CA if the call winds up there. In all these cases, it would be nigh-impossible for a CA business to make a case against you, because you (almost certainly) didn't establish minimum contacts with California such that the CA courts could exercise its
long-arm jurisdiction against you. Even if you had a contract with this company with a CA forum selection clause, it would be a huge stretch; you consented to CA jurisdiction to settle disputes over that contract, you didn't say "I submit to the laws and jurisdiction of California for everything ever."
What if you're a consumer in a one-party state, knowingly calling a number in a two-party state, to discuss business you have with that company? Well, I would wager you're still in the clear, and in fact I record a significant number of customer service calls as I sit in my one-party state, regardless of where the representative is located or what the telephone number is. I do this in order to protect against the abuses in TFA, "forgetful" supervisors, etc., and I do not worry about the wiretapping laws of some distant state. Why? Well, even though they
might be able to establish jurisdiction, that is just a threshold requirement.
There is still a choice of law aspect to the legal analysis, and there is a substantial consumer protection interest in my state's law protecting my ability to record conversations evidencing bad faith or abuse by out of state actors. I am a private citizen calling a large, well-funded, legally-savvy commercial entity (imbalance of power). I am not subjecting the (similarly-ill-equipped) private citizens of the two-party state to the business practice of secretly recording them. I don't have an incentive (as a business might) to circumvent the laws of the two-party state, and in fact I may be involuntarily at their mercy if e.g. my local monopoly power company only takes calls in a two-party state. There is no countervailing "privacy expectation" for call center drones in a corporate work environment, making and receiving
business-related calls all over the US and often overseas. The nature of the calls is not what most people would call "confidential," and objectively I think an ordinary, reasonable person assumes these calls are being recorded, and can be overheard or monitored at the call center. The business knows where I am, and has a commercial interest in doing business with me where I am (according to the laws of my state), but I almost never know where the business or its call centers are, and I have no interest in reaching into their home state. In other words, tenuous jurisdiction plus overwhelming factors favoring my home state's one-party law means that most of the questions you pose
should go in my favor as a one-party caller.
There have
been some cases in CA specifically that limit these kinds of interstate actions, including one where a MO (one-party) caller wanted to use the CA law against a CA business, but was denied, as well as some cases saying calls to customer service centers are not covered. My hunch is that there will be a case on this sometime in the near future, in some two-party state where a business gets really shellacked for dishonest BS and sues (maybe an unsympathetic defendant or a corporate client). We shall see.