I have never tried this, but it certainly has some good points. No air bubbles under the glass, or between laminations.
I have seen RC aircraft wings that were glassed and bagged, and the finish on them is flawless.
You would only be getting about 15 psi clamping force, but it would be that everywhere on the bow. Your form would mean that you would need a sizable vacuum bag, to place the assembly in and seal.
Your can use compressed air and a venturi as the vacuum generator, or purchase a designated vacuum pump.
Research some of the RC aircraft sites for techniques-the glider guru's seem to use this technique the most.