https://www.openstreetmap.org/relation/10967083 is questionable.  Chinatown doesn't really have universally recognized boundaries (most people would probably agree that Kearny is the eastern edge and Bush is roughly the southern edge, give-or-take half a block, but the others not so much).  

It's not an admin boundary, admin_level=10 doesn't exist.  SF is not divided into wards/districts/whatever like that below the city/county level.  Neighborhoods are informal and don't actually have fixed boundaries.