Sorry about the slow reply I have just started a third job so my time has been pretty much used up lately. The answer you might be looking for might possibly be unreachable by current programming of bluetooth shield. You might try this link https://github.com/don/BluetoothSerial I believe his code would help you as it has on connection on disconnection and a few other functions that are pretty nice. Hope this helps…
And as far as reconnection just call setupBlueToothConnection() to enter connect mode… after you reset from disconnect