You see! When you dream of other people, people not part of your intimate circle, you are dreaming of aspects of your life that are more distant but yet hold for you the keys to unlocking the things you need or want.
These more distant aspects are often power-gaps in yourself, areas where you lack or need these resources and must reach externally to draw them to you. The idea, long-term anyway, is to pull these more distant aspects of yourself closer, where you can more directly control them. The more far removed a person or thing is from your actual life, the further that aspect is from becoming a part of you. For example, having a dream involving a superior at your job often stands for your need to possess his/her power, at least inwardly. You lack what they may have, which could be self esteem, self worth, the ability to take charge, and because of this lack you do not have the resources to break out of your present loop. That superior, here, in this example, stands for a low self image that you are tying to build up, so that you too can command a similar level in abilities.
You dream of these people, so that you can, in essence, capture their qualities, or at least the qualities that they stand for. For example, many times you will have dreams involving well known people. Celebrities commonly stand as an icon for an idea or way of life that you desire or admire. By sharing in these people's energy, as you do in a group dream of this sort, some of that energy remains with you, helping you to acquire that quality or aspect. Dreams of people that you admire are very conductive to your self-image and the growth thereof.