SkyTeam is kinda/sorta matching:

SEA-BCN, SEA-MAD are showing up at just over $2k (a hair more than the OW fares). Thru EOS, so PacNWers, it's a good time to book a Europe vacation for next summer!

Edited to add: The Skyteam fares are to many places in Spain, also Mallorca, Ibiza and Canary Islands.