Following some conversations with the nice folks on the #textmate IRC channel, I’ve tweaked the name and layout of the Go TextMate bundle. The link above now points to the new version of the project, although the older layout remains available (for a while at least) here.
The advantage of the new layout is that you can very simply install the bundle using the git clone command:
> git clone git://github.com/AlanQuatermain/go-tmbundle.git \
~/Library/Application\ Support/TextMate/Bundles/Go.tmbundle
The Readme, history, and license are all stored inside the top level of the bundle.