It depends on the insure and the wording. Whether you are voluntary or paid has a bearing on it. Full business use should cover it, if you are not carrying passengers for hire and reward then you are covered. If you get paid for taking the occupants out, then you are not. If you are taking them places not as part of your work activity they are covered, if it is part of the work activity they are not. Confused? Insurers are always liable for the occupants of your vehicle under the road traffic act, they would have to cover any claim made by them, but they could repudiate claim for damage on your vehicle.
I personally, would be looking for a separate policy of cover if possible to cover the occupants as part of work. The company themselves should be looking into this for you, as it is their responsibility rather than yours.