Bandwidth contracts only LIMIT bandwidth they do not create bandwidth or improve priority of traffic. To do what you want with bandwidth contracts, you would have to figure out a way to:
- Identify the VIPs
- Limit everyone else
*If your VIPs login, you can figure out a way to assign them a role that has no bandwidth contract. Everyone else, you can limit their bandwidth by applying a bandwidth contract to their role.
In the other building, you can make a different AAA and Captive Portal profile where everyone besides the VIPs get a different bandwidth restriction than the first building.
*If you are using a preshared key network, there is almost no way to differentiate between VIPs and others, unless you enter and maintain a long mac address database and do mac authentication. After you do all of that and configure it properly, if the wifi is bad, your VIPs will still have a bad experience, because bad wifi does not differentiate between VIPs and regular people; it happens to everyone unless you take steps to make it good.