Companion trip LHR-JFK

I am looking for a good option on a return flight to New York from London.
Ideally one that earns me tier points but one I can use miles for a companion flight - both in PE.
The Virgin planner seems to only offer me K class fares (which I can't use to get a companion flight) or W class - flexible but more expensive. I see that S class fares qualify for a companion flight. Is there a way to search specifically for S class options? None of the flights I have found are S
Also there seems to have been a fairly hefty price rise in the past week - PE K fares to new York were around the 530 mark a week ago and have jumped to 800+ now.
Ideally one that earns me tier points but one I can use miles for a companion flight - both in PE.
The Virgin planner seems to only offer me K class fares (which I can't use to get a companion flight) or W class - flexible but more expensive. I see that S class fares qualify for a companion flight. Is there a way to search specifically for S class options? None of the flights I have found are S
Also there seems to have been a fairly hefty price rise in the past week - PE K fares to new York were around the 530 mark a week ago and have jumped to 800+ now.