Share iPhone's internet connection with a non apple device. Tethering

Question

I have a non Apple device used to process some data. It has bluetooth support.

It can be paired with the iPhone via bluetooth.

The device must use iPhone's internet connection to access a remote server.

See the flow:

1. I pair the device with the iPhone in Settings->Bluetooth.
2. I use ExternalAccessory framework to send data to the paired device.
3. The device processes the data and uses iPhone's internet connection to send the data to a remote server.

There is no problem in pairing the device to iPhone ( no jailbreak, by the way ).

Also, the firmware of the device is to be modelled in order to sent https requests via a valid internet connection.

The problem is the tethering, that will allow the iPhone to share it's WIFI or 3G connection with the device.

All I have found so far is tethering the iPhone with a computer, but no word about other non apple devices.

Any idea/link?

Take into account:

1. The device has bluetooth hardware and can be legally paired with the iPhone, no jailbreak needed.
2. The data processed by the device MUST avoid the application, and go directly to the remote server: I am not allowed to get the data from the device and use NSURLConnection to pass it to the remote server.

Please suggest a way to share iPhone's internet connection with non apple device.