Forgive me if this was covered upthread. I'm flying r/t SFO<>SOF in November on a W fare upgraded with two GPUs. The SFO>FRA and FRA>SFO segments are on UA metal, and cleared into BF immediately.

The FRA>SOF and SOF>FRA segments are on LH. Am I entitled to upgrades (albeit only to intra-European business class) on these as well, using the same GPUs? I know LH honors UA GPUs on a day-of-departure basis, but I'm not clear on whether the GPUs I used for the transatlantic legs also apply in this case.

If so, do I call to get printed certificates? And if not, why not, given that technically GPUs should cover the entire routing?