Here's a great link on this subject. It's 5 years old and from a Mazda6 forum, but the issues are essentially the same for TB coolant bypass on just about any car:
Why not to do the throttle body coolant bypass - Mazda6 / Atenza
Someone ran the numbers for the Mazda6. That car might have very different values than our car for all of the specifics in the equations, but the overall effect is likely similar. His formulas say you might gain less than 1/2 hp from such a mod. Of course then everyone else chimes in with other theories about effects that might fall outside his model, like reducing heat load in the engine bay in general by removing more hot coolant lines, etc...