We see from this answer that wine poured by a Jew who rejects Judaism is yayin nesech. Would that cause the wine to be forbidden even to himself, or is it only forbidden to others? Would he be violating halacha every time he drinks non-mevushal wine?
The Avnei Yashfei Chelek 2:61:4 asks a question and offers an answer that may answer this question.
He was asked if one can serve a cup of wine to someone who is a mechalel shabbas.Since once the mechalel shabbas touches the wine he renders it assur and in effect will be drinking yayin nesech.
Rav Feinhandler (the author) answers that it is possible to say that when we prohibit the wine of a mechalel shabbas we are placing a kenas (penalty) to stop his bad behaviors and we "consider" his wine to be like if a non-Jew touched it. He notes that he himself is able to drink the wine since a non-Jew is not prohibited from drinking the wine himself rather we aren't allowed to drink it. Therefore a mechalel shabbas isn't more stringent than a non-Jew and he wouldn't be prohibited from drinking the wine himself. He ends of by saying that it isn't too clear because maybe he gets the status of a non-Jew lechumrah only and would not be allowed to drink it. He also told over this svarah to Rav Eliyashiv who agreed to his psak but not to his reasoning which I just outlined (see the tshuva inside to see why Rav Eliyashiv agreed to allow him to drink it.)
It seems from your question that if he was an actual idol worshiper than its a non-starter and the wine should be prohibited based off an actual issur of receiving benefit from avodah zarah. If you meant a mechalel shabbas then maybe he would be permitted based off this svarah.