The bonus now shows how close you are to achieving your next bonus increment. Please note that the bonuses are not fixed and bound to change until we make an official announcement about it. Right now the priority is to gauge how much bonus can be given and to who.
So the site mentioned that buying lottery tickets also helps to achieve a higher bonus, but how does the number of lottery tickets bought factor into the percentage, as the percentage also represents the wagered amount if I am not mistaken.
Its all added up to make up for the requirements. I can't reveal the exact way it is calculated though to prevent people from gaming the system.