I read an article about building skateboard decks in a woodworking magazine.
The builder used a vacuum bagging kit to glue up his deck, and mentioned the fact that the vacuuming of the laminations helped prevent gaps, and air bubbles in the project.
Even if you only started your "clamping" with the vacuum bag, and then placed the bow blank in a rubber band, or air hose form, it would help evacuate most, if not all, unwanted air from the glue up. Which, in my books, would be a bonus.