The first thing I would do is find out if there are bass in the lake, this maybe easier if you could find who manages the lake, state or local.
If not have some stocked and sit back and let nature works its stuff, who ever manages the lake may stock it.
If bass are present but not in larger numbers you may have to stock more or see about getting a slot limit enforced on the lake, that is, bass within a certin length can not be kept.
Also, take a weekend and do nothing but catch the bluegill, this will give you a good idea of the size of the bluegill and they can tell you if there are any bass in the lake.
If there is a large number of small bluegill this can indicate that bass are not there or that there is a small population of bass.
You are right in that bass eat bluegill, they love to eat bluegill.
Its all about predator and prey, you always want a good blance.
Hope this helps,
Alfred