3 Building Scenario

I have a situation that I have not encountered before. We have 3 buildings, the farthest distance between buildings is about 90 feet. The main building has a wired LAN and that is where the server room is as well. The other 2 buildings have their own small LAN's, but there is no connectivity back to the main. The final objective is to tie in all 3 LAN's into one subnet, and also provide wireless coverage throughout the area. We typically use the Avaya AP-8 in this scenario for full coverage, but my question is - will wired clients in the 3 buildings be able to talk to wired clients in other buildings using the wireless LAN as a link? I feel like the answer is 'no', but I am beyond my realm of experience here. Since distance is minimal, I want to try and avoid the expense of the wireless point to point products, but if that is my only method then I'll have to bite the bullet. Any insight?