Can confirm that HSBC Premium account allows fee free transfer to other HSBC accounts, anywhere in the world. So it bloody well should... as the requirement is to have average balance >1 million HKD.
Actually, not that bad, as you can hold all sorts of securities/ currencies in the account (so not just HK shares, but also US government treasuries, corporate bonds, CD's etc.) But it does make it pretty much your main bank/ savings account, which defeats the purpose of wanting a free way of sending money to your (presumably main) account in the US.