I often have my Severus call Remus "wolf" affectionately, in both wolf and human form. I agree with azure_rosa that "Werewolf" seems to be used as a derogatory term, and I also haven't noticed the "Werewolf"-human "Wolf"-animal pattern. The only pattern I've noticed is that many fanfic writers have him call Remus "Moony" when he's in wolf form, and/or have Remus think of himself as "Moony" in wolf form, as if Remus and the wolf are two different entities sharing one body.