They can't force partners to open award availability. Thus if it's not there, it's not there. They can open it on DL flights. You could go SAN-LAX-JFK or SAN-LAX-AMS/CDG/LHR-FCO or SAN-SLC-AMS/CDG-FCO. I'd look at getting them to fly you SAN-SLC-AMS/CDG-FCO as most viable.