The two easy ways to muster up info about the bonus wagering requirement of a casino are:
Go through the bonus terms and conditions of an online casino. An authentic and reliable online gambling site will always have a set of clear and precise terms and conditions which are easy to locate.
Seek help from the helpdesk via chat option. If you find the helpdesk unclear, vague or unfriendly then do reconsider your sign up with that specific casino.