From what I understand you are looking to set up a PAN. Ubuntu is preloaded with features while eOS is minimalist. I believe what you are looking for is discussed here on superuser.
As you requested terminal scripts I found a GUI program that manages most all of this for you. It is old, but it works, as I am posting this via the Bluetooth from my iPhone 6s+.
sudo apt-get blueman (this guy uses bluez that we have already)
after installing the program, pair your device using the eOS built in manager:
[to be addressed in a moment, upload a pic on strong LTE via bluetooth is painful]
dont forget to verify on both the computer and phone.
configure your phone to allow hotspot and ensure your phone is broadcasting its hotspot via Bluetooth as well.
"super" + "space" will open app tray, type "blue" and you should see "Bluetooth Manager" in your options. Select this.
You should now see your paired device, right-click it and select the "Network Access Point" option.
eOS should now give you a notification that you are now connected to the internet!
As there was a viable solution I outlined it here, unless other situations inhibit this, using the wifi-hotspot or usb-hotspot on your mobile will give you a faster networking experience. Attempting to upload these screenshots via Bluetooth tether failed a few times while USB tether was near instant.
Thanks for the chance to help and learn a bit more about eOS and Linux!