I need to check my own DAI Keep stuff now.
Tal-Vashoth card: I do think he considers you a friend. He says no matter what happens from here on out (I think) there's nowhere he'd rather be. I didn't sense that coming from a place of deceit. I think he genuinely meant it. Your quizzy has opened avenues he wasn't able to think of before so it's like a whole new world for him. I think the lack of a definition comes more from not having a way to define it in the Qun. That's my story (or delusion
) and I'm sticking to it. I'm going to ignore that Hissrad part...he is and always will be Iron Bull to me 
When that mission came up/happened, I think Bull was caught in a bit of a crisis. You can sense it when you ask him about the alliance before you do the mission. I don't remember the exact wording but the premise of it was he was uncomfortable with the fact that the Qunari were even coming to the Storm Coast because he wasn't sure about them being so close. Now I don't know if it's in regards to how the Ben-Hassrath would perceive him as he is now or if he prefers who he is now and isn't sure how to relate to the Qunari at home anymore. I mean he had had enough of it before (his purpose) and asked to be re-educated before he was sent to Orlais to become Iron Bull.
If the rumors of going north for the next game are true (hadn't seen anything about the DLC), then the decision may factor in. You may find yourself pitted against a Qunified Bull or a new Bull will have to face his old life again. It is interesting indeed.
That's what I meant about the Tal-Vashoth card being the friendship one. I was referring to the Qun one being 'doesn't see you as a friend.' being all that's left then is Hissrad. Should have been a little more clear about that, sorry.
And yes, I refuse to see him in that light as well. He just seems...sad and closes himself off using the Qun as an excuse. It's obvious that he was never really happy with his live pre-Orlais (him breaking under stress/something like that; hating his role, etc.) and with his Chargers being the closest thing he has to a family; if you choose the Alliance over them YOU are letting his family die. Ouch. And it's something he never gets over that once he becomes reunited with the Qunari again; they'll send him to be Re-educated and whatever was left of the Iron Bull will be killed off for good.
Not only that, when he's Tal-Vashoth; he at least has his men and gains a bit of trust from some of your Companions. He HAS a support system and a network of friends to help him along the way and in time overcomes and comes to terms with his life; not regretting a thing. And of course if he ends up with the Inquisitor (or Dorian), that also adds something special that he never had before. Life is good *thumbs up*
Under the Qun; he has nothing. No friends, the Ben-Hassrath are most likely cautious with him and the lost of his men still lingers and is eating him alive. Also, when you speak to Gatt before the mission starts, he pretty much says/calls Bull 'A tool that still has use to them.' The Qun pretty much says that he's nothing but a tool.
Yeah, it's obvious that along he's useful (the Qunari don't waste resources); his health doesn't matter.
I know someone posted up a picture somewhere that in the DA:I files where the DLC would be under, there were something to do with Qunari. This is only speculation right now but either way; the Qunari are most likely going to play a part in the future either it be in DLC (I think this is more likely) or the next game.
Again, this is speculation.
And yeah, I'm curious on how those two choices will play out for his character.