It's not clear from your initial post how much flying you intend to do annually after you relocate to LIS. Can you tell us that, including estimated spend on airfare, total number of miles and segments?

If you expect to fly just one TATL a year in Premium Economy, and a few Economy Class intra-European and/or intra-U.S. flights per year, you might be hard-pressed to attain even low-level status in any FFP.