the bumblebee gobies are a brackish water fish, and should be kept at a specific gravity of between 1.010 and 1.012, which is about half that of a marine aquaria. it can be hard to get these fish onto dried foods, and they may never accept anything other than live, frozen or freeze-dried live foods. if you wanted to keep these fish in a community, then mollies, glass fish, parambassis (chanda) ranga, orange chromide, etroplus maculatus, and rainbowfish would make good tankmates, and would do well in a brackish water aquaria. you could also try the four-eyed fish, Anableps anableps.
hope this helps.