O is US domestic upgrade either with miles or status. Which means 100% as you booked into Y. Never seen it on an international route though. I/J are the upgrade fares for international routes. Though I'm sure you know all this since you're US Gold, but FYI...must be a codeshare thing.
Assuming you didn't book the entire itinerary on miles you'll earn at least 100%. 150% if you paid cash for a J ticket.
Go Gators