I have found all kinds of low volt bulbs that fit 120v sockets. I think you are just fine doing this.
Yesterday I was working on a custom 277v lighting project over in our work area and needed about 20 feet of wire. We have a cage with tons of leftover partial rolls of wire etc. I found a box manufacturer labeled "low volt control wire" that looked ideal. I pulled about 6 feet of wire out and it had seriously thick insulation and found the UL listing typed on the outer shell listing approved for 300v and I believe that. So low voltage can mean anything usually under 600v. I see this all the time. But in the field "low volt" is anything under 50vac/vdc. I would say that trying to use 120v loads in applications from 12vdc sockets, casings, terminals or lugs is a really bad idea. Go down not up.