Can my wife and I both take $5000 Usd into china

in short, yes. $5000 or 20,000 rmb each. i would suggest that even though you are married and traveling together that you both hold your $5000 dollars seperately as going through customs/passport area. only need an over zealous chinese customs guard to catch 1 of you with double the ammount and it could end up with confusion, 1 of you past customs, 1 still in customs and seperated from each other.