I donīt know the particular Bronica lens, but for medium format portraits (head and shoulder or facial) I would recommend a 150mm over an 80mm. The 80mm is better suited for full length body shots. Tight facial portraits done with an 80mm will in most cases look distorted. It may still be okay for head and shoulder shots though.
In any case, and I say that as a great fan of Zeiss lenses, I would prefer a portrait made with a Zenzanon lens that has ideal proportions over any distorted portrait made with a Zeiss lens of too short a focal length for the purpose.
Regarding the bokeh of the East German mf lenses (especially Biometar 80 and 120, Sonnar 180) I must say that these are sublime. The only lenses that are close are the 2000-Series Hasselblad lenses (110/2, 150/2,8), but these are much more expensive than the East German lenses. I had a look on pictures made with the mentioned Bronica lens on Flickr and they look nice too!