Not sure how I didn't come across this earlier but it's a god send. Way easier to use long descriptive branch names once autocomplete is enabled!
Step 1) Download
git-completion.bash from the git repo
curl https://raw.github.com/git/git/master/contrib/completion/git-completion.bash \
Step 2) Add it to your
if [ -f ~/.git-completion.bash ]; then
Open up a new terminal window or
source ~/.bash_profile and you're good to go!