The Bluno has the ability to act as an iBeacon (transmitter), but it doesn't have the ability to receive iBeacon announcements and pass these to the Arduino.
BLE devices can communicate and can receive UUIDs and RSSIs, but it depends on the capability of the device and the interfaces it exposes. An iOS device, for example, exposes a very sophisticated BLE API. The Bluno board does not. It exposes a "serial port" to the Arduino and maps send/receive data to a set of BLE GATT characteristics. A pair of Bluno devices can be configured to act as a wireless serial link, or software on a computer or mobile device can exchange data with the Arduino via the bluetooth stack.
There is an AT command that will return the rssi of the paired device, but the documentation isn't clear as to whether this is available to the Arduino or only via the USB connection to a computer.
The best reference (such as it is) for the Bluno specifically, seems to be the DFRobot Wiki
I doubt you will be able to connect to the AR.Drone using Bluetooth Low Energy directly from a Bluno doesn't have Bluetooth LE. In theory you could connect another Bluno to the USB port on the AR.Drone and write software, but it would be simpler to get a WiFi shield for an Arduino and use the WiFi networking that is built in to the AR.Drone