You can find the bonus terms and conditions directly under Cashier > Bonus history.

If you have activated a deposit bonus, you cannot withdraw your entire balance.

You can only withdraw your real money balance. 
The bonus balance only becomes real money once you have fulfilled the bonus terms and conditions.

You can view your wagering progress at any time under Bonus history.

As an example from the Welcome Bonus: 1st deposit / Claim Casino Bonus | CHF 1400.- + Free Spins | swisscasinos.ch

Wagering requirement: You must wager 35 times the bonus amount within 30 days in order to be able to withdraw your winnings.
Example: If you deposit CHF 100.- and receive a bonus of CHF 100.-, you must wager a total of CHF 3500.- (CHF 100.- x 35) to meet the bonus terms and conditions.

For the exact amounts, please always check directly in the bonus terms and conditions.