I have tested this and after playing one round my balance turned to 2500 bits (after my bet of 3000 bits) and when I tried to withdraw I am getting message

Because you received a bonus you still have to play 1 Spin & Tap Tournament(s) before beeing allowed to perform a withdraw. We know this may be an inconvinient to some of our users but we are doing this just to make sure people don't create fake or duplicated accounts just for the sake of the free bits.