rather than worry what bonus you'll get. maybe better to look at where the broker is based and what deposit protection you'll have. this information is usually at the bottom of the broker home page, if it isn't there steer well clear.
you are probably likely to start off small and so the deposit will be likely small, as such, any danger of losing your deposit may not be of concern to you. if you are indeed based in Canada as your flag suggests, maybe a good plan would be to choose a local broker rather than go offshore in the unlikely event of broker failure.
"regulated by the Investment Industry Regulatory Organization of Canada (IIROC) and customer deposits are insured by the Canadian Investor Protection Fund (CIPF)" or some such similar for your location.