The Allegra Lounge definitely is the place to go. If ZRH is your final destination and you need to claim your luggage, you face a problem: your case will arrive on a belt in Terminal B, AFTER passport control. The Allegra Lounge is in Terminal A, AFTER passport control. You'd need to claim your luggage, go "backwards" through immigration and then through immigration again in Terminal A (after walking from B to A airside). I don't think it can be done.

If you're connecting, you're fine.