The ban on “Family Guy” pretty much doesn’t apply anymore I have been able to enjoy the 2 new episodes that have been shown so far along with all the older episodes that come on late at night.
I was just going to say that at first I thought Brian and Stewie were enemies but after seeing them go on adventures together and viewing the newest episodes, I would say that they are “best friends who don’t want to admit being best friends”.
From “Brian - Portrait of a Dog”:
Stewie : “Is the doggie going bye-bye? Oh I’m so sad.” (waits until Brian is behind the car) “Quick back up!”
And of course, there’s always “Road to Rhode Island”
Yeah, they are definitely friends. Whether it’s because they’re taking one another out of a very limited pool of potential friends, or because they actually get on well together, it’s really what works episode to episode.
True, but in the end of the same epsiode Stewie acknowledges Brian by saying “Dog” and nodding his head and basically I took that as Stewie’s way of saying “It’s good to have you back” without actually saying it. 
They have a love-hate relationship.
“Brian, wait! hkkkkk ptoo!”
“Look, I just need some time to think, all right?”
“Yes, yes, you’ve got lots to think about. Public drunkenness, grand theft auto…”
“You forgot about when I made you crash your head into the windshield.”
“I don’t recall” SLAM “Well, yes, I guess I had that coming.”
Brian: “says something I can’t remember”
Stewie: “Well, you don’t have a soul.”
Brian: “Ouch.”