Yes, Gwynedd and Dyfed are unfortunately the only "Welsh-over-English" roadsign counties. Even in places like Machynlleth (Powys) and Corwen (Clwyd), the signs have English first, simply because they are English-over-Welsh counties.
And there are many places where I have noticed signs in English only - especially in Gwent and eastern Clwyd. Maybe the Welsh Office should be pressured a little more... This signpost business is so superficial; so long as commercial signs remain in English (even if the shopowners etc are Welsh-speakers) nothing will be accomplished.
Discussion topic: Quebec-like laws making it compulsory for ALL commercial signs to include Welsh - or even be in Welsh ONLY - that'd certainly bother the Saxon!