Finnair (AY) does use the Terminal 8 (mainly AA International and Miami) JFK Admirals Club Lounge.

I think that Iberia(IB) uses that same lounge as well.

Both AY and IB uses Terminal 8 at JFK.

LOT POlish also uses Terminal 8 and I believe the Admirals Club there too.

With your oneworld Saphire status, you could get into others (like British Airways' over in Terminal 7, which Qantas also uses and Cathay Pacific too.) Or even Aer Lingus' and Lan Chile's respective lounges in Termoianl 4. But terminal to terminal transfers at JFK are a huge hassle.