Can I use the AC facilities in T4 when arriving on a AA domestic flight and connecting to a QF flight? (I am QF Platinum travelling in J so I expect I should be able to get into the T4 AC lounge).

Might be good to grab a quick shower there before heading over to TBI terminal. I only have a two hour connection but the luggage will be checked through and boarding pass issued at DFW, so the only thing I will need to do is pass through security at TBI.