Most of the casino works with big money, So they won’t scam for the little money. Which you mean as the bonus to the participants, the bonus is nothing to the trusted gambling or casino. If you want to check to find the bonus program of certain website, you should apply for it. Then check whether they paying you the bonus or not. The good gambling site ready to pay you even 1000 dollars as a bonus for the big deposit. Bonus program is used by the website to get attractions among gamblers, I don’t think they will scam on such program.
Its not about a casino having big money or not, it's a matter of whom they were, you can imagine if the accumulation of thousands and millions of people were being denied access to their deposit from a casino, each having little or more money on their casino wallet, this will definitely sum up to a very huge amount of money, therefore you need to research well on a casino before choosing them in other for them not to cart away your money over night among others.