Hk is a voluntary signatory to all international Human Rights conventions, which make discrimination, at least in terms of employment, illegal. Hong Kong subscribes to common law, and the ICCPR is entrenched in the HK Bill of Rights.
HK, like all first-world regions, is subject to these international standards.
By the way, the Yumla management would have a heart attack if they heard that you were mentioning them in the same sentence as volar, dragon japseye, or hei hei. They are not the least bit cliquety. Take it from a scruffy eurasian regular. No cheesy RnB. No dress code. They do get packed though, so profiling at the door may exist, but only to make sure the regular moneyspinners are propping up the bar!