I've only had such a greeting once, and that was on CX in Y. I think then I was only OW Ruby. It was nice and surprised me actually.
I've only flown CX once since (no greeting) but will do so at the end of the year in J so shall see what happens then.
Recently flew AA - nothing at all there, apart from a warm welcome at the Admirals Lounge in LAX & SFO.