I looked at pictures of Bendizao on a Chinese site. It looked like a slightly more yellowish color mandarin, like Satsuma, the color of the interior appeared a little more darker orange and watery-juicy like a regular conventional mandarin, and it looked like from the picture that the peel was tight and thinner and would not so easily come off.
The appearance of the inside and the thin tight peel could suggest some parentage from Changsha mandarin, perhaps. The size of Bendizao mandarins are small and delicate, suggesting it might have parentage from a small size mandarin.
From the looks of the fruit I would infer that its distant ancestry is mostly regular mandarin, with definitely a little bit of pomelo (not uncommon for many mandarin varieties in Asia), but it definitely did not descend from any type of orange. The tight peel suggests that the parents were probably not a Satsuma or Kishu type mandarin.
I'm just not seeing any characteristic traits that might suggest Yuzu parentage, although Changsha mandarin parentage is possible.
Changsha is a deeper color orange though so it would not have gotten its color from that.
If it can really survive -10°C, that would probably make it very comparable to Keraji mandarin, and if this is really true, I think this mandarin variety may hold a lot of potential.
http://www.05760576.com/2006/11/23/140952595.html