You will need to read the terms and conditions on how to avail of and use your Betway bonus. All welcome bonuses are FlexiBonuses:
"When you have an active Flexi Bonus and place a bet, the amount you bet will come from your cash balance and your bonus balance at your BCR ratio at the time of the wager being placed. Winnings are also allocated back to your cash and bonus balance in the same ratio as they were placed."
Here is an example:
If you bet $100, $50 is from your cash and $50 from your bonus. If you win $200 from this bet, $100 (50% of the win) will be rewarded in cash and $100 (the other 50%) will go to your bonus. You can withdraw the $100 cash balance but the $100 bonus balance will be subject to wagering requirements.
Flexi Bonuses are also only valid for seven days after the point of activation. If you do not use this by this time, you will lose the Flexi Bonus.
With Flexi Bonus, you can withdraw your cash balance at any time. But you will also forfeit the bonus.