I tried as well to add my wife to my accounts as an additional proof of relationship. CIBC told me that she needs to be present in the country and Scotia might allow, but I have to do some more digging. I spoke with the branch manager and she told me that I need to create a brand new Moneymaster account (this is an account which can only be opened on line at Scotia), to put some money there and then I could add her but the money would be blocked in that account untill she enters Canada. She has her interview scheduled in June, so I am thinking at that option as well, to have a bank paper showing a joint account with both our names. I tried on line and they require a SIN number (which I know it is not mandatory to provide to the banks) so could not open it, so I have to go to the branch and try there.
But as a genberal rule, to add somebody to a bank account in Canada, that person has to be present in the country, show a form of residence status and passport.
Hope this helps.