Fred wrote:... is it wrong to use the first two bolts in a route if the finish (40' or so) is completely separate?
I'd say this is a generally accepted practice at a lot of crags. This
topo (PDF) for the Cheakamus crags near Squamish has several examples of routes sharing bolts.
Whether or not the new line is a route or a variation would be a matter of debate, but as long as it doesn't detract from the existing route, I doubt anyone would complain. In the past, the criteria was often whether or not new bolts could be clipped from an existing route. The reasoning being that if they could be clipped, the new line was probably too close and would change the nature of the existing climb.