Which international J lounges have champagne? I haven't been to one (by choice) for years, so I have no idea.
EK do, but their network offers F across the board with very few F lounges. Because that's where their F pax go, you can't really consider that to be a true J lounge.
How about CX, SQ, QR, EY, SQ, LH/LX, NH, TG? I've only been to the F lounges of these airlines, may have wandered into J to have a look but that's about it.
I know JL, BA and AA don't.
Can't imagine that champagne is standard across true international J lounges across the world, for those without separate arrangements for F pax.