Thai Airways Royal Orchid Plus - Lounge Options

We will be flying the following:
HKT-BKK; TG C (also Star Gold)
connecting in BKK to
BKK-Hanoi; Air France Y (no status on Sky Team)

Will we be able to use the Thai Lounge upon arrival in BKK?

Thanks!

No. All the TG lounges are departure lounges and admission is based on your departing flight, not your arriving flight.