^^
If I am getting it correctly, you will need to wager the deposited amount once then any bet you will make will count towards the wagering requirement (except bets on some games).
From their explanation on how their bonuses work, specifically point 8, you will need to finish the wagering requirement (x15) before you can withdraw your funds. It doesn't matter if it's the bonus oney or your initial deposit.
Its clearly stated there to avoid any bonus abuse and for the gambler to actually try the site and not just came for the bonus and withdraw their funds instantly. I not tempted with that bonus though, I still prefer to observe everything about this site and probably, some gamblers will also share their experience with this site. Having their bonus promotions can help them attract more gamblers, I believe they should do be more often and be more generous when it comes to their promotions.