Nope — United generally does not offer complimentary upgrades to people traveling on non-United carriers (Copa is the sole exception) and United generally does not offer complimentary upgrades on transpacific tickets, whether paid or award.
If the Asiana flight is oversold in your booked class of service, the fact that you are an elite-level frequent flyer with an Asiana partner airline (United) may lead to your being "operationally upgraded" (pushed into a higher class of service because they oversold coach), but op ups are pretty rare. That's your only hope for a "free" upgrade flying on a Star Alliance economy award ticket.
Safe travels.
Originally Posted by
alwaysBEcaffeinated
I recently booked a UA fligh(operated by Asiana) from ICN - SEA with points for my wife and I.
Not to split hairs, but if you booked a MileagePlus award ticket on the ICN-SEA nonstop, you almost certainly have a United ticket on an Asiana flight marketed by Asiana … not a United ticket on a UA flight operated by Asiana.
MileagePlus award tickets don't book onto "codeshare" flights (like a flight with a UA flight number that are operated by OZ operated); award tickets for travel operated by partner carriers usually book directly onto the flight number of the partner carrier.