Originally Posted by spk
Citibank Platinum cardholder has access to TG's Royal Silk Class lounge. The "first class" lounge access is for CX First lounge and the first class side of the Louis Tavern lounge.
Krungsri Gold and Platinum (Bank of Aydhaya) cardholder has access to TG's Royal Silk lounge whenever flying TG. Same day outbound TG boarding pass is required.
I currently have the Krungsri Platinum card, thanks for the information! ^