Originally Posted by
RobertH
My significant other looked at my reply and LAUGHED. She said (and I think she's right) that lots of time Delta has A class availability and yet SkyBonus upgrades are not available. Delta seems to be really, really tight with these upgrades. The only way to tell if an upgrade is available is to call SkyBonus. Don't be surprised, though, when they say NO.
The domestic upgrade certificate us standard upgrade inventory: RP/R/O/OP
The terms state the "select fare" certificates work on:
"This certificate entitles you to a complimentary one-way Delta One™/Business/First class upgrade with the purchase of a published Y/B/M/S/H/Q/K fare for travel within or between US49/Canada, excluding Hawaii."
I'm not certain of the pecking order of SkyBonus certificate versus GUC and RUCs.