Short answer
Sometimes. Family members may be able to combine their bridging visa applications, but each person usually still needs to meet the criteria for the bridging visa.
People claiming to be members of the family unit of a Bridging A, B, C, D or E applicant can combine their application with that person.
However, most bridging visas do not have secondary criteria. This means each family member generally needs to satisfy the main criteria for the bridging visa themselves.
If family members are eligible for different bridging visa types, they may need separate applications or clear nomination of which bridging visa each person is applying for. A withdrawal by one family member does not automatically withdraw the applications of other family members.