It's not as simple as having a config option would be, but you can create a script to do this.
Go into /Applications/Sublime\ Text\ 2.app/Contents/MacOS and rename the 'Sublime Text 2' executable to anything else (I called it st2). Now create a new text file called 'Sublime Text 2' and paste the following into it
/Applications/Sublime\ Text\ 2.app/Contents/MacOS/st2 --command toggle_full_screen
Save it and run
chmod u+x Sublime\ Text\ 2.
Your dock shortcut and Spotlight will now start Sublime in full screen.