Dixon is correct, the lounge is not suitable accom. That being said, the way I understand it, your FDT limit starts the second you check in.
7.8.1. Category of Standby Facilities
Standby should be undertaken at the crew member’s own place of residence, or where “suitable accommodation” is available. If these conditions are not fulfilled, then appropriate limitations shall be applied to the duration of standby duty.
7.8.3. Standby Duty Time limits
If suitable accommodation is not available, then the appropriate limitation of the flight duty period is applicable to the total of standby and duty period..
Airport standby sucks, I have a couple of ASBY's this month. Looking on the bright side, it might give me time to get caught up on some of that pesky paperwork that I have been putting off.