Can this item stat be made so it protects against the Hunter Spider "Touch Attack Entangle Ability?"
It will make sense regarding the nature of the Webbing spell and the similarity of this one.
It reads spell immunity web, doesn't protect against mundane webs! For similiar reason tanglefoot bags also work on things immune to entangle.
For druids and rangers they can move across webs, but thats doesn't means a giant sized spider can't entangle them in rope like silk.