I used to use zsh but switched back to bash a couple years ago simply because the benefit wasn't worth the trouble. When I first changed back I went to some difficulty to get my PS1 to have color in it. That slowly faded away and now I have a visceral, negative reaction to prompts with that much colorful whizzy fu. Maybe in a few more years I'll trim out the username/hostname/path and become content with just a %.
This is exactly what I've done for the past year. I realized that most of the time, I know which directory I'm in, I know which user I am, and I know which host I'm on. It's trivial to look up any of these (as well as other crazy things people embed in their PS1).
Now my prompt is nothing but a green ">> " on a black background. I'm not deluding myself when I say that the reduced clutter improves my productivity.
To each their own. I'm logged in to at least 5 different hosts at any given time, often many more. Without user/hostname in the prompt and the term-title I'd be completely lost.
In your case, your goal is to reduce the cognitive weight of your environment.
A host name in the prompt is one more string you need to read and it's a user interface mistake as a term is for entering commands and reading their output.
I've seen people successfully using different background colors for visually telling their terms apart. It's a very good solution as there's no reading cost.
I personally use workspaces to sort terms by host and this can be very powerful if combined with tagging. This also works well but I suspect it's linked to my workflow.
Your concern about git however is unrelated to shell choice. I customize bash quite a bit (my own completions, etc.) and maintain dotfiles in a git repository. I have a post-receive hook that tars up my dotfiles and puts them at a public location on my http server that only I know about so that I can easily get them when I'm on a machine without git. I'm not going to do that for every machine, but if I'm stuck debugging something on some odd machine, at the very last I want my vim settings around.
It makes more sense for vim than zsh though. What color your prompt is has a lot less bearing on your productivity than your editor configuration. (Though I don't do much of that either).
I am of the same practice as fusiongyro. I also expand on that and have a very simple configuration for Vim. Once you go beyond a handful of machines, you never know what to expect on the system. "Lowest common denominator" wins out for me almost everytime.
