If you have already bonded with the wolf, just cast 630 again and tell him to return. If that does not work, tell him to leave(i usually twice) and see if you get the message that the wolf has gone to rest. If he has THEN use 630 and tell him to return. Also make sure you are in a place he can get to(outdoors for instance).
If that does not work, then I would do an assist. Good Luck!
I often have to TELL companion to return a few times if i've been away a few days. Also on a few rare occasions your in a place a companion cannot enter and they wont respond to you until you move to another room.