I am going to be honest, so don't get mad at me  

If you are going to use that account, it can't be considered as your wife's account anymore. It will be an alt of yours and you will be responsible for whatever you do with it.

There are no rules against using alts to join campaigns as long as you don't use them to join the same campaign.

If I may ask, why don't you use your main account to join altcoin bounties? Are you afraid of being treated as a bounty hunter?

Why don't you ask your wife to start using her account and show her how to join these campaigns? I think that may solve the problem.