I'm still kind of confused. Are you asking that when someone addresses an email to both your address, and also your wife's address, then that email will ONLY be delivered to the Mac, but not also be delivered to your respective iPad and iPhones?
If that's what you are asking then NO there is not a way to do that. When someone addresses an email to more than one email address, the email is sent by the server to each of those recipients separately. The server has no way of knowing that you all are a couple, nor does it have a way to deliver mail to only a specific device but not others. If you have your Mac configured to receive mail to you then it will receive ALL of your mail, as will your iPhone. The same goes for your Wife's accounts.
The only possible solution to this would be for you to create a third (shared) email account (for the both of you) and tell friends that they should use that when trying to reach both of you. Then, only set that account up on the Mac (but not either of your phones or iPads).