Sorry to rain on your
Computer Scientists discover the Wonders of Biology parade, but...
tailor a bacteria to attack or compete with a bacteria which you needed to control
This already exists in the from of a virus which attacks bacteria, also known as a Bacteriophage. It doesn't even have to be programmed from the outside to keep up with the evading, evolving bacteria; it just evolves as well. And even if you wanted to "program" this feature, you'd have to deal with the nasty problem of protein folding in silico. Better to leave this entire process highly parallel in wetware.
programmable immune system
Also known as Vaccination, and this happens naturally after every infection. And again you don't have to program anything, it uses a random walk to find matching antibodies which attach themselves to bugs.
This discovery will sooner result in a very parallel, but also clockrate wise very slow computer than in immunological advances. And if this gets used in the human body via gene therapy it will be used to regulate genes, i.e. as an if/else block, not to calculate anything fancy.