For each point-to-point link between buildings or sites, you'll need one bridge on either end of the link.
You do not need any access points unless you wish to offer wireless access to users... point to point bridging is completely separate from user access.
Assuming there are no line-of-sight issues, there's no reason you shouldn't be able to accomplish what you're describing. Designing the specific solution may be a job for a hired consultant, though.