Just because a defendant is able to post bail that is not to say their case is over. They will still need to return to court in order to have the matter resolved.
When someone fails to appear the presiding judge will immediately revoke their bond. They will then issue a bench warrant providing for their immediate arrest. Airports and ports of entry frequently run warrant checks on passengers and people who are pulled over for routine traffic stops are also subject to warrant screens. If someone has a warrant out for arrest they could potentially be arrested on any day, at any time, for any reason.
If someone misses court because of an unforeseen situation such as illness, a flat tire, or simple forgetfulness this can be easily fixed. As soon as they realize they failed to appear they will want to call their bondsman as soon as possible to request something called a reassumption of liability. They will need to bring this to the court in order to have the bond reinstated and their court date to be put back on the calender.
If someone misses court and posted cash bail instead of working with an expert Riverside bail bondsman that money will be considered forfeited.