IMO (which others are free to agree or not), Bluetooth is a less than ideal choice for robust command control due to its relatively short range and one-to-one design.
While I have zero experience using Bluetooth to operate trains, I have lot of first-hand experience using Bluetooth keyboards, mice, trackpads, iPhones, iPads, headphones, Android devices, medical devices, and hearing aids. It's a great technology when used as intended.
It have little doubt that it works well for smaller layouts, however, I have my doubts that it has the range for anything that's much larger.
