The Maximum Payouts/Deposits apply to the betM Mates feature and to any other bet placed by any one individual or entity (or group deemed by betM to be acting on behalf of anyone individual or entity) on any one Race.
You can view the Maximum Win Limits via Menu (Tap on the 3 lines on the top left) of betM Homepage once logged in > Rules > 11. Maximum Win Limits (Australia and New Zealand).