There are no legal real-money online casinos in California, so withdrawals aren't possible. Instead, sweepstakes casinos allow redemptions. If you play with Sweeps Coins or another premium currency, you can later redeem them for cash prizes or gift cards.
Gambling online for real money is not yet legal in California, including online casinos, online poker, and online sportsbooks. There is hope that sports betting may be legalized when Proposition 26 and 27 are put before state voters.
The bonus money received as part of the 1Win offer can be spent for betting on sports. If there is not enough money in your main account, the bonus balance is used for betting.