AFAIK if it is a scam, you are going to have problems with withdrawals (though legit poker sites also tend to make withdrawal somewhat of a problem, so idk tbh). Worst case scenario is that an unlegit poker site is a pyramid scheme that will allow people to withdraw money until it won't. I'm not sure how much all of that applies to JP, I've been seeing the website around for at least a year now (though haven't really played there), so unless it is a long-term pyramid scheme-esque scam (which can easily be, you've mentioned the suspicious bonus structure, which if it is, it is reminiscent of a pyramid scheme) it may be legit to an extent, just shady.