Every couple of weeks, I hear someone complaining about some difficulties with Bundler. Yesterday, it happened twice. But somehow I just never have those difficulties. I'm not saying Bundler is perfect; certainly in its early days it wasn't even close. But for the past two years it's been incredibly solid and trouble-free for me, and I think a large part of the reason is the way I use it. Bundler arguably does too much, and just as with Git, a big part of it is knowing what not to do, and configuring things to avoid the trouble spots.
Sublime Text 2 ships with a CLI called subl (why not "sublime", go figure). This utility is hidden in the following folder (assuming you installed Sublime in /Applications like normal folk. If this following line opens Sublime Text for you, then bingo, you're ready.
open /Applications/Sublime\ Text\ 2.app/Contents/SharedSupport/bin/subl
You can find more (official) details about subl here: http://www.sublimetext.com/docs/2/osx_command_line.html