Coloque isso em seu .bash_profile
parse_git_branch() {
git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/(\1)/'
}
export PS1="\[\033[00m\]\u@\h\[\033[01;34m\] \W \[\033[31m\]\$(parse_git_branch) \[\033[00m\]$\[\033[00m\] "
Exemplo:
Retirado de: http://betterexplained.com/articles/aha-moments-when-learning-git/