Winning prizes, bonuses, or free spins depends not on wins or losses but solely on the value of the bets (spins) placed on the specific game.
Bonuses and free spins have a wagering requirement, meaning you need to bet a specified amount a certain number of times (as stated in the promotion terms). Additionally, the promotion terms will specify the Maximum Win from the spins/bonuses that can be transferred to your cash account.
The wagering requirement and the maximum win are highlighted in the notification at the time of the award.
In both cases, you can track your wagering progress in the My Account - Casino Promotions section, or on the Casino homepage.