This file contains the preferences for TextMate:
~/Library/Preferences/com.macromates.TextMate.plist
There are some other files in "~/Library/Preferences/“ which are prefixed with “com.macromates.TextMate”. Not sure if you need those.
This directory contains bundles, plugins, themes, favorites and similar:
~/Library/Application Support/TextMate
Not sure how well it works to transfer favorites. They are just symlinks. That directory also contains sessions, not sure if they can be transferred. Although they seem to be plain text files.
These are the only two locations I know about. Keep in mind that the ~/Library directory is hidden by default in Finder. It’s visible in the terminal.