To access the Bonus History, simply go to the "Account " (top right corner), then "My Money", "Bonuses, Freebets, and Offers", and at the bottom of the page, you will find the "Bonus History".
On mobile devices, just select the "Account Menu" (top right corner), then "Bonuses and Free Bets", and at the bottom of the page, you will find the "Bonus History".