GOOD luck at the vet - I would change the bed if that's the only thing different - but wanted to tell you - the reverse sneeze is really easy to hear - wheezing is a totally different sound.
Think of reverse sneezing like a snorting noise - they stand different - they snort really LOUD and and it almost sounds like hyperventilating - both my girls do it and the first time I heard it I FREAKED.
you can stop them from doing it by gently closing off the nostrils so they breath thru their mouth - I found kissing works just as well too
good luck and I hope he feels better