I don't think those are air bubbles, but maybe a little dry on the resin. The good news is don't worry about it - you're using epoxy and it's connected.
I had some spots that looked like that when doing one of my tank area bulkheads. I wasn't working fast enough and the resin was starting to kick before I got the next layer down, and once it kicked no amount of rolling was going to squeeze that air out. I ended up cussing, grinding, and doing it again. The hotter is is outside, the thicker you lay it up, and the more catalyst you use (in poly and vinyl) the faster things go.