[TorontoCFE]

They would take your word for it. You could have your wife demonstrate her poker skill and, assuming you seem more knowledgeable, you would be ok.

Don't forget bonuses can be treated differently than poker earnings (just like tournament winnings can be nontaxable even if your cash game earnings are).

I would think that all bonuses are technically taxable - you go after thme essentially because you think you will at worse break even on play so that you earn the bonus. That said, most bonuses aren't significant enough to be worth claiming.