The COM port protocol over Bluetooth basic rate / enhanced data rate (BR/EDR, aka "Bluetooth Classic") would be the Serial Port Profile (SPP). There is no equivalent in the specification for Bluetooth low energy (LE).
Nordic Semiconductor defined UART capabilities that have caught on with other manufacturers as well. They call it the "Nordic UART Service" (NUS), however, this is not part of the Bluetooth standard and does not provide paired COM port as with the SPP. (https://devzone.nordicsemi.com/question/59047/what-is-nus-nordic-uart-service/)