Yes they are air bubbles.
You will probably find this has a lot to do with your resin. Expulsion of air is a property of the resin, and some systems just don't do it very well. Which then means you need to put on very thin coats so that the air doesn't have to move very far to the surface, and use of a heat gun will help as well. Then I will also normally get to the stage you have, clean the part very well with compressed air then soap and water, then a prep solvent, and then apply one final layer of resin very very thin. Not looking to build any more thickness, just looking to almost wipe resin into those pinholes. Allow to cure, then a quick knock back with 1200, then spray a 2k clear coat.
In general, I think air inclusion is just part of the process. You can get pretty good results, but I dont know if I have ever got a perfect result with absolutely no air. So you may need to adjust your expectations as well. Not to say you can't improve you've got there, but just don't beat yourself up over a handful of pinholes if you do come across them.