The answers here fix the problem.
$ git clone git://github.com/kballard/osx-plist.git
$ cd osx-plist/ext/plist
$ ruby extconf.rb && make
$ mkdir -p "$HOME/Library/Application Support/TextMate/Managed/Bundles/Bundle Support.tmbundle/Support/shared/lib/osx"
$ cp plist.bundle "$_"