Report the 1095-A for you and your wife on your return. Is the Policy number on the separate 1095-A for your son the same as yours or is it different, if so then you can report the 1095-A on your son's return?
From my own experience, I have seen where a return has been rejected or processing held up because the child listed on the policy did not report the 1095-A on their return, even though they were listed on their parent's 1095-A.
What I do know is your son's return will mostly be rejected or there will be a delay in processing because he had a 1095-A in his name and he did not report it on his return. On the other hand, I do not know what happens when the parents are claiming the dependent and you file the 1095-A under the dependent's return.
What I would do is file the 1095-A for your son on his return and the other for you and your wife on yours. I believe this will be the best-case scenario. If you get a letter asking about the 1095-A for your son, then you can say that he reported the 1095-A under his return and provide a copy of Form 8962 that was filed with your son's return.