Once you have successfully made the deposit and claimed the bonus, the funds will be credited instantly into your account. It just takes a few seconds for the funds to appear in your casino account. If this doesn’t happen, you must contact their customer care support and ask for clarification.
On the contrary, you will find certain casinos that require players to get in touch with their customer care service after depositing the money to request the bonus to be added to their casino account, but this is rare these days.