You can have multiple Sub Minis in your overall system, each assigned to a different room, as long as the devices in the room allow ie. you cannot bond a Sub Mini with a Sonos portable device for instance.

What you cannot do is split one Sub Mini to work seamlessly across multiple rooms. A Sub Mini can only be bonded with one room at a time. To use with another room, you would have to manually assign the Sub Mini to another room if you wished to use with other speakers/room. Any change in room configuration (removing/adding a product) will also reset any Trueplay Tuning for the room.