You would think that they would be, wouldn't you? Won't buy them until the bags are recyclable.
From the Walkers website:-
▼ Question: Are your crisp bags recyclable?
Answer: Currently our Walkers Crisps packets are comprised of an inner foil layer, and an outer plastic layer (plus some sealant between). As you will appreciate, technically, virtually anything can be recycled, however, because separation of these materials is both costly and energy intensive it would make little sense to do so, environmentally or economically. And there is not the infrastructure for the ordinary consumer to actually recycle the material in question. So our current Walkers Crisps packets are not, in a meaningful sense, recyclable