Well yeah, the vampires pin each other by the neck as well, though they see it more of a threat than dominance. Because vampires bite the neck more often for blood and to kill things that are alive. So when an Elder does it more often than not it is a threat, that was why he had attacked when she went to bite him there. He will probably not see it as one coming from Avina, because they bonded, he considers her to be his wolf. But when he does submit to the wolf, he will cover his throat so she can't bite it. But if you want her to alpha command him, it will have to be the back of the neck.

Oh it will be so much fun, to have them fighting for dominance. If Brice gets behind Devin he will attack him for sure. Though I can see them both starting it. If Brice starts with Devin I don't think Avina would be able to stop Devin from attacking back. (Unless she went all Alpha on him)