Although it might seem tax deductible because it’s a payment going to the government, bail is not tax deductible. Bail is a guarantee (like a bribe, essentially) to get a defendant to appear in court for a crime they are accused of committing. As long as the defendant is compliant with this and his or her other bail release terms and conditions, they they will get their bail money refunded back to them.
In the case that they choose to bail out of jail using a third party bail bond agency, then they will be losing a little bit of money, in the longer run. The defendant pays the bail bond agency 10-15% of their full bail amount and the bail bond agency will then cover the remainder of the price for the time being. The defendant will need to go to court and respect release conditions just the same, but this time, at the close of trial, they will not be given their money back from the bail bond company.
Bail bonds exist as an alternative method for most people who need to bail out of jail. Getting enough money to pay bail without a bail bond company is stressful and strenuating. Most people use a bail bond company, like Brea Bail Bond Store in California.