I see Hanners and Bubbles as a possibility for deep friendship that explores some issues, but I don't see them as candidates for makeouts (or anything more serious than that, come to it). Both characters have stuff going on that's an effective block to relationships that involve sexuality, although Hanners seems to be working on getting past them and, for the moment, Bubbles doesn't.
So, anyway, I guess I see Bubbles as potentially benefiting from Hanners' influence or perspective, and Hanners getting some entirely different and serious perspective on emotional issues as well. But I think that's work that both of them need to do. If they do it together, they'd be in that weird space of having become too emotionally close to one another without becoming romantic - and that usually precludes romance.
Also, we've seen no evidence that Hanners' attraction template includes females of any kind, whether biological or synthetic. She's mentioned "Cowboys" and "Firemen", so I'm guessing she's androsexual. Could be gynosexual as well I guess, but if so we've seen no evidence of it. And she once described makeouts something like "I guess they're kind of like tigers for me. Beautiful when seen from a distance, but it would be really bad to have one up close and happening to you."
And as far as I know, we've seen no evidence that Bubbles is sexual at all. Aside from having her "gender bit" set to female and presuming the software templates have the same statistical variation found in human populations, that means about 90% chance she's androsexual, and 20% or so that she's gynosexual (some overlap occurs; some folk miss both). But there's no reason for a synthetic to have a libido at all if they don't want it. For them the libido may be possible to just switch off, and right now I think Bubbles doesn't want one. She has really basic trust and guilt issues that likely block her from exercising her sexuality until they're worked out.