If you are on an international flight, the type of ticket is irrelevant provided you are booked in BF, and you can use the Presidents club. This also includes upgrades to BF (or UpperClass on Virgin) and at Newark you also have the opportunity of using Virgin's lounge if going to LGW - that lounge is awesome...play computer games, listen to CD's, watch a movie...great place to spend couple of hours).

They also let upgrades use the arrivals facility at Gatwick.

The bigger problem is when on the way into the US you connect and want to use the lounge - unlike UA which lets you use their clubs and gives their foreign PremExec elites one year comp membership - CO tend not to let you in unless you have those comp vouchers or pay. When there is a delay I have been allowed in though.