I was in the area a little while back and the bike parking spots here didn't appear to be bicycle_parking=anchors, they were circular metal bike stands from what I saw (unless of course they were swapped out for something else in that time). So the correct tag for this should be bicycle_parking=stand then? The bike stands I saw there were just a circular variant of the generally more common square/rectangular metal bike stands, not bike anchors on the concrete, etc..