I think that's Bruce on bass, but I believe that Carl and Brian played bass too.
I know that Hofner bass was used for almost or whole record.
How do you know that? About the bass, I mean. If you have a source, that's great, but I would need a pretty good source to believe that, considering the band owned at least 8 basses at the time.
And I really don't hear Brian playing bass on Wild Honey at all. Nothing in his style. Carl seems unlikely too for most of the parts. As far as AFM contracts go, the only WH ones I've seen are the string overdub ones for a couple and the Boogaloo one, on which I would guess Al played bass.
The viola-style bass that the group was using during this period was an Eko copy of the Hofner. It can be seen in photos from some '67 concerts.
Actually, they owned both the Eko and the actual Hofner. Strangely enough.