Santa Monica has two O'Brien's Pubs, and so far as I can determine they're not related. Both have weekly pub trivia. The one on Wilshire has trivia provided by an excellent local company on Monday nights (and if you look closely on the back wall, you can find my name on a couple of plaques). One memorable night actor Josh Duhamel and his then-fiance Fergie from the Black Eyed Peas joined in for a game. It's also part of a league with an annual Tournament with a $1,000 prize.
The one in the WSJ article is the O'Brien's on Main Street. Their trivia is self-produced, as the article notes, and on Wednesdays. The trivia even has its own web site separate from the pub:
http://obrienspubquiz.com/ . I haven't made it out to that one yet, bit it's been on my to-do list for a couple of years. Won't make it until at least October, though, because right now I'm involved in a completely different trivia league that currently also has a tournament with a $1,000 top prize.
LA may be site poor so far as NTN/Buzztime is concerned, but if you want to compete in pub trivia for good prize money there are LOTS of opportunities.
TFM