With an AMD card, can I force V-Sync only for Rage?

Solution 1:

As of latest patch, V-Sync has now been added to the game options.

The new "VSync" option in the video settings menu allows you to remove screen tearing. There are three options: ON, OFF and SMART.

Source

Note: See edit for previous solutions.

Yes, there is a trustworthy third party tool. Check out RadeonPro.

http://www.radeonpro.info/download/

It has a SLEW of options you can configure, add, or override per game.