and yes, you dont have enough speakers and amps for atmos at home. sound bars wont make it. hell, most people i know have their 5.1 systems setup wrong.
I'm a sound designer in Hollywood, my credits include Men in Black 3 and Zero Dark Thirty.
The main promise of ATMOS was that it wouldn't matter how many speakers you had -- a mixer could prepare a final mix in Atmos in his 60-horn room, but then when the bitstream on the DCP or Blu-Ray was decoded in the theater or home, it wouldn't matter if the end-user had a 60-speaker Atmos rig, a 9.1, a Barco Auro speaker system, a 5.1, a stereo or even a mono. The Dolby renderering algos would simply take the panned objects and automatically render the correct audio stream for each speaker, as a function of the speaker's position relative to the listener. The Dolby RMU is just a glorified OpenAL audio engine, it gets fed audio streams that have an alt/azimuth data envelope, and this envelope is transformed down to whatever speaker array the end user has.
What's even more interesting is you could have a significantly more complex speaker array than the person who mixed it -- maybe he mixed it with 32 speakers, and you have some future-ready system with 100 -- and the renderer will still do the Right Thing and expand the spatial resolution accordingly. Atmos mixes are future-proof for any simple, non-phase-related speaker array.