I've been fairly neutral on Bill Maher over the years. Sometimes he says something witty and incredibly funny. Sometimes he's a boorish, whining bully with a modern day left-wing digital pulpit.
As for as Religilous goes, I thought it followed the same pattern. Some parts were hilarious and/or on point with some questions and concerns I've had with religions over the years. On the other hand, he seemed to go out of his way to get a variety of folks with questionable brain power on the screen to mock religion without feeling the need to have serious conversations with highly-intelligent theologians. Even in cases where the person sitting across from him was reasonable, there's always post-production to make it look like the person was a wingnut.
He's out to make a buck from his followers and detractors alike with his unoriginal mocking brand of comedy, and he's very good at it if you rank success by the amount of money he rakes in. As with most people with a serious agenda, he'll nudge the facts here and there to fall in line with his opinions, make a movie you either love or hate, and he'll laugh all the way to the bank.