I would say
STL-JFK 892 mi base rdm+1,784 stl bonus rdm+892 mi base eqm+892 mi stl bonus eqm= 2,676 rdm+1,784 eqm
JFK-BCN 3,831 mi base rdm+7,662 stl bonus rdm+3,831 jfk bonus rdm+3,831 mi base eqm+3,831 mi stl bonus eqm= 15,324 rdm+ 7,662 eqm
2,676 rdm+1,784 eqm+15,324 rdm+ 7,662 eqm= 18,000 rdm + 9,446 eqm each way x 2 = 36,000 rdm + 18,892 eqm round trip.
Plus of course you can earn much more with creative routing like STL-DFW-MIA-ORD-JFK-BCN, etc...
Anyone want to check my numbers?