You could add a small dose of zolpidem (Ambien) with your temazepam or clonazepam, but I really doubt it would enhance the effects of the benzos. Ambien has some weird effects and it may ruin your benzo buzz.
Personally I wouldn't do it, but that's just me and I don't like any of the z-drugs. They all are shitty, if you ask me. Some leave your mouth tasting like shit the next day, others make you delirious. Nahh...not for me.
But if you're into stuff like that, go ahead and mix away, but make sure you don't mix massive amounts. Remember with drugs like this less is more.