Don't gloat just yet. Brom's a nobody in SA, so if Allison disappears in the next little while you'll find yourself somewhat alone I suspect. Lysander for example doesn't really know anything about Brom other than that the Solarians hate his guts, which isn't calculated to make him popular or anything. 
If Allison sticks around, well, that's a different story. She's got more than enough influence to force SA to accept you and even acknowledge you as a potential power player... Could be interesting.
I'm not gloating(yet). I will say though that regardless of the turnout, I am very happy with how much fun this issue is already setting me up to have with many different characters across multiple realms.
Also, you're argument is flawed in the case that you're assuming Brom's only powerful contact in SA is Allison. Not that you'll be learning who the others are, but hey the more the merrier eh? Also, he'll certainly be making sure to do everything to keep Allison around if at all possible. Kind of has an important reason to at this point.
