Technically all the current familiar archetypes were written before the shaman was released and the freelancers had a hold of it (I know because I wrote the most recent familiar archetypes days before officially working at Paizo and getting access to the Advanced Class Guide), so the archetypes themselves don't say anything directly either way, while in the other direction on the shaman's side, familiar archetypes are in Player Companions only, so a Pathfinder RPG line book won't mention them either. While it's not even remotely a rules forum answer, I would think that in most cases, since a spirit animal counts as a familiar, if a familiar archetype applies to a witch's familiar, it should definitely be OK to allow it for spirit animals too (aka, no figment but everything else).