Many gambling sites have deposit bonuses.
However, if you receive the deposit bonus, there is a condition for withdrawal.
For example, 10 times the deposit amount, etc.
What is the reasonable condition you think?
Thats most of the terms and condition on every gambling site while receiving the deposit bonuses simply because its just a market promotion and they wanted you to play on their site not just for their bonuses. As long as you can withdraw your capital then I think nothing to worry about, beside you can on that site to gamble.