My impression is that it only works from your phone and IPhone is the only one so far. I never FB on anything but my computer, so it’s a non issue to me.
I did a little snooping on myself just for kicks. My work pc logs in from 2 different states, home only 1 place, and my cell. It was able to pickup only my cell locations but only if I made a posting.
I suppose if you spend enough time on FB and click every link you come across it will eventually pick up your location