It's a beautiful song, and I think it's possible to read it as talking about both a card game and a simpler part of his life - the five green queens would probably be the Irish one pund notes from the early 80s, which had Queen Medb (Maeve) on them, and with all his worldly goods in a black bin bag, the only other thing that mattered to him was Jean - presumably an early/innocent love?
It's a beautiful song, and I think it's possible to read it as talking about both a card game and a simpler part of his life - the five green queens would probably be the Irish one pund notes from the early 80s, which had Queen Medb (Maeve) on them, and with all his worldly goods in a black bin bag, the only other thing that mattered to him was Jean - presumably an early/innocent love?