I have no experience with banties at all...I've raised Australorps, X-Rocks, and Leghorns, and that's pretty much it...but I can't imagine there'd be a problem with putting them together. The problem would be if one of them is a rooster and you have a standard rooster. Standards and banties can and do interbreed, so I'd think you might have a few small tiffs until all the hens settled out the hierarchy, then no problems.

I have kept, at various times, Muscovy ducks, Royal Palm turkeys, and Ringneck pheasants in the run with the chickens and/or each other, and nobody ever had a problem with anybody else, in there...