UPDATE
After multiple failed attempts to get both Bluetooth Dongles to work simultaneously I emailed TP Link's customer service to see if this was even possible. This was their response:
"Computer can't use more than one Bluetooth. If the user wants to connect 14 Bluetooths at once, we can only recommend that he use two computers. 7 Bluetooth connections is a hardware limit and we have no way to lift this limit."
In short, NO, it is not possible two use a second dongle as an extender to the 7 device limit.