Last year (2015) I was able to claim the wife as a dependant. The taxable deduction was like $11,500. They allowed the deduction, despite her landing in Canada in September, and Marriage in June.
When I spoke to my dad about it, he suggested that it's probably a sliding scale, because, yes they were dependant to a certain extent, but that would be offset against the amount they eventually earned. This is old-school CRA, so take it with a grain. That said, I should be able to let every one know in a couple wks when our accountant submits our 2016 returns.