I recall flying a PA A310 BCN to JFK in June 1991. I think they had just started the BCN route earlier that year. I used FF miles on that trip, before PA went bankrupt and leaving me with a big wad of potentially useless miles.
Yes, the route was indeed short lived. Pan Am agreed to sell its TATL portfolio (less the LHR routes which, apart from 2 that were excluded per Bermuda II, which went to UA a year earlier), the European network was sold to Delta in August 1991. Pan Am shut down for good in December (5th) 1991.
Compared to TWA, Pan Am was not as strong in Southern Europe. It flew to Madrid, Rome, and Milan (Milan was added long after Rome, as I recall), and served ATH via FRA, not nonstop, and didn't serve LIS or BCN until very late. I am not 100% certain they flew to LIS, though I seem to recall they did because DL had TP fly the route for them in the mid-1990s at JFK but not sure if it was a route authority they had or a new service post Pan Am.