If the ^ ⎋ (control-escape) shortcut isn’t working to pop open the Bundle Items Menu in TextMate, try disabling Apple Remote Desktop in System Preferences->Sharing. Having keyboard access to that menu eliminates a ton of mousing.

Sometimes I need remote access on my machine, so disabling Apple Remote Desktop is not ideal. I couldn’t find any information about what ARD is doing with that shortcut, or why ARD would need any shortcuts on a client machine. The bindings could also be changed in TextMate, but I’ve always preferred to keep application defaults for those occasions when I’m using a different machine.