No. Usually there is a wagering requirement tied to the bonus money. This means that you need to play the bonus money a certain number of times before you can withdraw it.
Getting a free bonus is a great way to get introduced to a game at a casino but it is not free money and shouldn’t be considered so. For example: I am given a 20-euro Casino bonus with a 10x wagering requirement. This means I need to have bet a total of 200 euro on eligible games, before I can withdraw any winnings gained.