I don't want to talk you out of a play, but other things point more to an under. Both pitchers do have horrible ERAs. However, only 2 of Bonser's last 7 appearances have gone over. He also tends to get low to avergae run support, just over 4 runs in last 5 games.
Wells is pitching for a new team. His ERA is a horrible 6.69, but he has started 4 straight unders. He's also only given up 4 earned runs in his last three starts, including a shutout in his last start. I will admit it is unlikely he'll do that again. But after Minnesota's pathetic showing last night against a poor pitcher, who knows.