I like the HK bars but not sure how busy they would be on a sunday. I really like Posh and the Ritz in HK as well. My birthday was on a thursday last year and vlada and posh were both pretty slow but Ritz was busy. Went And if you want to be a true ft'er a lot of the HK bars (I know Posh, Ritz and Vlada) are part of rewards network so make sure to use your credit card

Posh used to comp all your drinks on your birthday but not sure if they still do. My flight was REALLY delayed on my birthday last year and I had spent way too much time enjoying the free alcohol in the Skyclub and on the plane so only had one drink at each of the bars

One of the my favorite places to stay at in the HK area is the Hilton garden on 8th. The free breakfast is one of the best I have ever had (you order off a menu with vouchers if you are a hilton elite HH member) and the location is great to the theaters and HK bars and 8th avenue subways. Convenient location but it isn't right in the heart of the times square crowd.