If the obligations of the bid bond are not met the contractor and surety (the provider of the bid bond) are liable jointly for the bond. Penalties will be applied for failure to comply with bond obligations.
Also, when the project owner has to go and find a new contractor to finish the work, if there are additional costs the owner of the bid bond must pay as well. The standard for the additional cost is calculated by the difference in the bid that was held and the new bid.