Website lists 189 ATM's in Hong Kong, but all, except one, seem to be operated by:
AEON CREDIT SERVICE (ASIA) CO LTD
That is good to know. There are so many banks and ATMs in Hong Kong that I didn't have the opportunity to try all of them

. I tried HSBC, Bank of China, and the one that Bank of America Hong Kong became (I forget the name), and at least two branches of each before giving up.