Originally Posted by
lililolo
...In that case it would be more beneficial to buy from Eva Airways (full distance) than from United, (5 miles/$) correct? Eva Airways offers a premium economy T fare where United does not even offer a premier economy cabin from SFO to TPE. ....
It depends on what percentage of base miles is offered by the partner. (T, Premium economy earns 100% base miles for BR RDMs)
Additionally BR / EVA does not allow UA to sell certain fares, so this may be a moot choice
In general the mileage base approach (if mileage earning fare) works better for deep discount fares and the more premium fares work better using the fare dollar (PQD) based approach.