The issue is (partially) that Wolf and Raven was, while released later in the Shadowrun series of stories, some of the very first Shadowrun fiction ever written. It's my understanding that -- at the time it was being composed -- the Shadowrun game developers hadn't really pinned down what exactly a werewolf was or how it worked.
Stackpole intended for Wolf to be a werewolf/Shaman, but when the rules were more clearly laid out (describing all that a were-critter is and what it does), that didn't really "jive" so smoothly. I think that, for those trying to recreate Wolf using SR4, a Shamanic Way Adept is the way to go -- enhanced senses, killing hands (that look like claws), etc, etc...and tie it all to having an innate, natural, magical, bond with the Wolf mentor spirit. After he gets a little Karma under his belt you can look into the actual Shapeshift spell, Eyes of the Pack, Animal Attunement, and some other cool wolf-y stuff.