The iBeacons do not report to anything. They periodically broadcast a BLE “advertisement” that identifies the specific beacon. Some other device, like a phone or a Happy Bubble, receives the advertisement and does something with the information. In the case of OwnTracks, the phone receives beacon advertisements and the software publishes beacon information to MQTT.
So you could have fixed beacons and someone with a phone will receive the advertisements from those beacons as they pass and then relay the beacon info to some other system like openHAB via MQTT. You could also have several statically located beacon receivers, like Happy Bubbles, in various locations and have them receive advertisements from a beacon (for example, in a keyfob or a phone configured as a beacon). Yet another possibility is to have mobile beacons and mobile beacon receivers. I have an iBeacon in my car and my phone will notify openHAB (via OwnTracks) any time I’m in my car wherever the car may be at the time.