Install Pygments following these intructions: pygments.org/download/
sudo mkdir -p /Library/Application\ Support/TextMate/Bundles cd /Library/Application\ Support/TextMate/Bundles git clone git://github.com/acangiano/pygments-textmate-bundle.git "Pygments.tmbundle"
If TextMate is running while you perform the update, you may want to also execute the following line:
osascript -e 'tell app "TextMate" to reload bundles'
This is equivalent to selecting Bundles → Bundle Editor → Reload Bundles from within TextMate.