An easy way to share a bundle is to:
- Drag it directly from the bundle editor onto e.g. your Desktop.
- From Finder select to Create Archive of «your bundle» by bringing up the action menu (e.g. by control-clicking its icon).
- The resulting zip archive can now be uploaded to a web server or emailed to your friends.
Hint: you can also drag individual items from the bundle editor if you wish to only send a particular command or snippet to someone.
Generally though, if you update the bundle, you will have to repeat the above steps, and if you use the same bundle on multiple machines, you will have to keep track of which machine has the latest version (yes, .Mac syncing would be nice here).
So a much better way is to store the bundle in a subversion repository. This also gives you a way to undo heavy local experimentation :) There is a nice step-by-step post about how to share custom bundles with TextMate over at Robby on Rails.