Correct, only one bonus per account. I called and was told to apply for a new card that's considered a new account, sure enough, got my new bonus points from RBC, though that's a credit hit vs none for a credit card switch
I don't think this is entirely true...perhaps the key to getting a welcome bonus for a product switch on a card you've already held on the same account is to wait longer between switches. I know someone who switches between RBC Avion and RBC WestJet annually on the same accont and has received the welcome bonus points for the same product more than once.
I've still not tried it - as I'm doing a 3-4 card annual product switch (2012/13-BA Visa; 2013/14-Target MC; 2014/15-RBC Avion Visa; 2015/16-WestJet Visa), and I plan to switch back to a BA Visa in late 2016/early 2017 hoping they don't keep much of a 'history' of what cards you've had in your account.