The simple answer imo is yes - the complicated answer would be his *reasons* for saving her.
I feel like if Kai saved Bonnie in 6x22, it would be VERY different from when he saved her in 6x13 on her bday. In 6x13, saving Bonnie was a huge sacrifice Kai made bc of his newfound guilt and other growing feelings about her. But if Kai saved her in 6x22, that man would do it out of SPITE lmfao. Like sure, maybe a *tiny* fragment of leftover post-merge Kai would save her bc he believed she deserved better, but at the mental state that he was in by 6x22, i think a larger part of him would actually be looking to save her out of this petty urge to make bonnie suffer, bc dying would be too easy for her according to his thought process 💀
In canon, remember how Kai got annoyed by damon seemingly deciding to let bonnie die and choosing elena over her super quickly? He complains, saying smthg like "This decision was supposed to torture him," bc he wanted damon to agonize over the bonnie vs elena choice for a long time. Similarly, i think bonnie dying just like that would eliminate a lot of the angst, pain and tension of the situation, so Kai would save her life *just* so bonnie and damon would be forced to live with the uncomfortable reality of damon choosing elena over her and deal with the emotional fallout of that instead of pretending they have the world's best friendship, as they'd been doing for all of S6 (bc Kai would enjoy watching that mess).
Ofc, that would probably result in Bonnie aiming a lot of her resentment towards Kai for forcing her to face those hard truths, but maybe, after an initial explosion (and a lil nudging from Kai), she might realize that targeting kai is just shooting the messenger rather than addressing the root problem (her toxic friends). If it hadn't been kai, then somebody else would've made bonnie see the truth but either way, that's something she needed to see.
Realistically, even after this realization, i don't think bonnie would've suddenly warmed up to kai, but i think it might've pushed her to ditch damon instead of sticking around Mystic Falls to help him all the time (which would've consequently made Kai suddenly lose interest in Mystic Falls too xD). If Damon then chose to seek her out to beg her (read: force her) to defeat the town's new villains-of-the-week, or if he found her w his humanity off and tried to kill her to get elena back, i think kai might've surprised them all by appearing out of nowhere to get damon off bonnie's case (bc kai being kai was prob keeping tabs on bonnie's whereabouts as soon as she skipped town).
And maybe Kai's sudden appearance would've led to a bonkai confrontation with Kai realizing he may have saved her out of spite in 6x22, but there is no explanation for why he saved her from damon this time besides.. *wanting* bonnie to get her life away from her friends. And maybe that would've also led him to unsubtly point out that an elena-free existence had actually made bonnie's life better, thanks to kai.
Bon would probably kick his ass halfway across the world after a comment like that but i think it would stick with her, making its way under her skin as it sinks in that the horrific thing Kai did really did end up working out for her in the long run. Bc as we know, even at his lowest, there was always some part of Kai that begrudgingly wanted bonnie's attention and validation and rly resented her friends getting that from her while walking all over her. It would take a long time, but slowly and surely, i think Bonnie's intuition would eventually pick up on that tiny part of Kai that saved her life to show her that she deserved better. It would be very uncomfortable for her to realize that Big Bad Kai could no longer be an easy scapegoat for all her problems, but that might be just what she needs to finally see Kai as a person, rather than a monster. And from there? Well, looots of opportunities and potential would open up from there 😏
