The rest of the shops on the row are just tagged with addr:street=Yewbarrow Terrace, so my first inclination would be to make it consistent with those.

I guess if I was mapping this from scratch, I’d probably tag them all as addr:street=Yewbarrow Terrace addr:parentstreet=Main Street though, given that they are probably primarily addressed as ‘Yewbarrow Terrace’ rather than ‘Main Street’ (hence parentstreet rather than substreet).