Upgrade using onepass miles
 

Can I upgrade on a Delta operated flight within US by using CO onepass miles? I booked the ticket on Continental.com. The "TO" flight is on CO, but the return is on Delta. If I can upgrade, do I call up Delta or CO?

I just called up the elite line for CO. And they said I cannot do that. I should have called up before posting this Q here... So thats that.

You could still upgrade the CO flight.

Yes I could. But I am flying from SAT-IAH-RDU. The IAH-RDU is on one of those little planes (1-2 combination) with no first class. I don't want to spend the miles for a 30 min flight from SAT-IAH. (I might even get upgraded as my flight is at 5:45 AM, hopefully, no business travellers).