Mostly, it depends on the wagering amount. Generally, you must win the bonus back multiple times no matter what type of bonus you got. Think of it as another way to encourage you to play more. Relax and enjoy your favorite casino games and then collect the gains. However, situations vary. Some online casino operators apply 40x wagering requirements which you can still cover when playing a lot. But once the number increases to 100 times, it's pretty hard to meet the play-through requirements.