Snip
Some casinos allows you to withdraw when you have win with the bonus and meet up the required wagering amount while some will still ask you to wage again or asked you to deposit first before you can withdraw and as was said, casinos have different ToS.
If we are referring to the 10FS bonus, players wont be able to withdraw the winning without deposit because as per terms the wagering requirement should be met with real money while the winning amount from the FS is credited as bonus balance.
I have to agree with you if casinos may have different ToS related to bonus but nowadays this is the most used standard term for free spins bonus where players will still be asked to deposit in order to wager in order to unlock the bonus from the FS.
This is why it is recommended to read the terms before we take a bonus whether it is free spins or deposit bonus or any other bonuses to avoid complaint later due to not reading the terms in advance.