I agree with gophish11 on the amenities of the lounges. Depending on what/how/when you are planning on eating I'd hit the AA lounge if you aren't planning to eat until you get on the plane. OW Lounge food is better but with a two hour connection you really don't have more than an hour at most for lounge time. Depending on where you're coming from your inbound might be coming into T5 which will add another 15-20 minutes walk.
I'd probably just hit the Flagship Lounge and then walk over to TBIT.