This past weekend my LBS (not our tandem shop) was out of 700/28-32 tubes and wanted to sell me a 700/35-45 for our 700/32 tires. He insisted that it will fit and since its a tandem its even better, because tandems and hybrids can use a thicker tube wall for more abuse (less stretching=thinker wall).
Should work, watch out you don't pinch the tube when you install it. A modest amount of air helps this. It'll be a few grams heavier, but if you're running 32's you probably aren't counting grams too much. FWIW you may find a lot of difference in tube sizes, whatever is marked on them.