If you want something similar to what oh-my-zsh provides but for bash, check out bash-it.
https://github.com/Bash-it/bash-it
Bash-it is a collection of community Bash commands and scripts for Bash 3.2+. (And a shameless ripoff of oh-my-zsh
)
Includes autocompletion, themes, aliases, custom functions, a few stolen pieces from Steve Losh, and more.
Bash-it provides a solid framework for using, developing and maintaining shell scripts and custom commands for your daily work. If you're using the Bourne Again Shell (Bash) on a regular basis and have been looking for an easy way on how to keep all of these nice little scripts and aliases under control, then Bash-it is for you! Stop polluting your /bin directory and your .bashrc file, fork/clone Bash-it and start hacking away.