I arrive in LAX from SYD at 7.45am, and have about 3hrs unti

Yes, i will receive my boarding pass for the AA flight (LAX>Austin) in Sydney. I arrive into LAX at Terminal B. Bag will be checked all the way through. Do I head straight for TBIT lounge? 

Do you need to clear security to check-in at T4, and then clear again to go to TBIT, and again to get back to T4?

Thanks for the replies. Sounds like TBIT is a better lounge but given the time and my wait, T4 would be the better option. However, I don't have QF Platinum, only Silver. That means Admirals Clubs?? On the way back I fly out on business on QF operated by AA. Again, T4. I'd have plenty of time at ...

I fly to LAX on QF Business class and have a connecting flight to Austin out of T4 about 3 hours later. Which lounge is better to wait in - TBIT or T4?