These are rewards for the number of victories in Union Battles during a single day. There is a progress bar in the waiting window that fills up every time your teams wins and shows how many victories you need to have before claiming a bonus. Only the victories you participated in count towards the Daily Bonuses. You can win more than one bonus in a day: each next one will be better than the previous.
Beach Battles: What is a daily bonus?
Last Updated: 1210d