Originally Posted by
hookthem
Even if it is married and same flight number, the upgrades are processed separately. So, you will be eligible for a CPU on each segment (or that's what has happened to me in this scenario, which was very often SAT-IAH-DFW). So, you're good either way if your experience is consistent with mine.
Conventional wisdom says that this is only the case if upgrade (CPU) space is available on *both* legs at upgrade time. If only one leg is available and the flight was booked as a through flight then the flyer will not receive the upgrade.
You are likely hitting the jackpot with SAT-IAH and IAH-DFW being available at the same time.
-RM