It's hard to give you a definitive "yes" or "no" since how you apply the AGMBC to define the LEED boundary depends on whether you're certifying one new building in an existing campus, certifying multiple new buildings at one time, or one-by-one to a set of standards, and also depends on the particular credit.

In general, you define a LEED boundary for each building, but certain credits can share the boundary of the campus. You'll need to look at the AGMBC guidelines for each credit to see where each building can reference areas that may be shared by other buildings. In some cases you have to allocate certain things like alternative vehicle spaces to individual buildings so that there's no "double dipping" but in other cases such as campus stormwater facilities or open space those may be shared by the different buildings.

To add to the confusion, the AGMBC was written for version 2 projects, and still hasn't been updated for 2009 rating systems, so there may be some contradictions between it and the current MPR Supplemental Guidance. If you run into specific issues on a particular credit, you may get more help from GBCI or LEEDUser for those specific questions.