I hadn't watched that film for the very same reason. Took the plunge after 2 episodes of The Penguin. Must admit, Pattinson didn't do the film any harm. In fact, he wasn't bad at all.I'm not a big fan of Pattinson, so that may require a very very dull evening, to earn a viewing, no doubt it will happen though!
Gained some insight from the film for the rest of the TV series, but it wasn't mandatory viewing.