No luck here doing a Google search on the subject. Sure do get a lot of links to the M$ app store. Didn't realize how tight in bed M$ and Google are.
Is this a multiplayer games where you are playing with (or against) other people around the world? (I'm not sure single-player bingo even makes sense, and a cursory glance at the app's page suggests that it is indeed multiplayer.) Because if it is, then that's why you can't pause: it's a real-time game. It's like how Wordament can't be paused, since everyone all over the world is getting the exact same Wordament board and the exact same time, which is what makes score comparisons meaningful.