Guten abend! Vie ghet ist ihnen? Ich sprache KLEIN Deutch! (Okay, that's as far as I can go in German.) Since you are painting it will be easier to fix. You should do as mentioned in the other response and inject the spaces with some epoxy to fill the air holes. Be very careful when sanding not to sand through the cloth where the bubbles are. If you do I would cut out that portion and patch with a small piece of cloth. Perhaps before sanding go an extra coat of epoxy to give you more sanding thickness to sand it smooth. I don't know without seeing the bubbles how far they protrude from the surface.

Habe ein guten tag.
(? did I say that right? It's been a long time)
-Malcolm Schweizer