HI totallymytravis,
This is very much a "your mileage may vary" situation. It depends on factors like, how many credit cards you're being added on to; what the status of those cards is, how big the lines are, how they compare to your current credit profile, and a host of other factors. Basically, the better your wife's credit lines look in comparison to yours, the more likely you are to enjoy significant credit score gains as a result of benefiting your "authorized user" status on her accounts.
You will see whatever benefits you will realize from this once the credit lines report to the "credit reporting agencies" (CRAs). Note that some of your wife's credit lines may not report your authorized user status, in which case that status will have no effect on your score with that CRA.
Generally speaking, you should avoid having her add you to cards that have late payments or a high utilization of the credit line (e.g., a $2,000 limit card on which she's carrying an $1,850 balance). The best strategy is to only add lines with perfect histories and low balances.