Let me explain my situation:

I got my wolves back from a CP trainer, and I even asked them to apply dom to my alphas Nirali and Skylos

And now they have no dominance? Is this a bug or is it normal?

This isn't a bug. Dominance is reset when wolves are sold to another pack, so it reset when they were given back to you.

Not a bug, if you sell a wolf, all the dominance from it is gone. You have to keep a wolf in your pack to keep it's dominance.