No. Only the vehicle with the pass owner is covered. The second vehicle is subject to an entrance fee, or must have (or buy) a second pass.
Each Annual Pass admits pass owner/s and passengers in a non-commercial vehicle at per-vehicle fee areas; and pass owner + 3 adults, not to exceed 4 adults, where per-person fees are charged. (Children under 16 are always admitted free).
If you, the pass holder, decides to drive separately from your group then your group will need to have their own pass or pay to enter the park.