The Shach is also discussing Stam Yainam which is Assur to drink but Mutar b’Hana’ah
See Gr”a on the next line about mumar, which (by his reference) he defines as mumar l’avodes kochavim. I see no indication that he is toleh stam yayin davka on avodas kochavim.
So,what IS your point?
Not that yayin is mutar, rather that the same reasoning for the issur should apply to bishul.