This can be found under the topbonus website
https://topbonus.airberlin.com at "Redeem miles" - "Etihad":
Redeem miles with Etihad Airways
Redeem your miles and fly with Etihad Airways from Dusseldorf, Frankfurt and Munich or Zurich and Geneva to heavenly travel destinations in the Middle East, Africa, Asia or Australia. Benefit now from the reduced mile offers:
For 25,000 miles* you can fly to the Gulf states, to South and Central Asia
For 30,000 miles* you can fly to Africa and the Middle East
For 35,000 miles* you can fly to South East Asia and the Far East
For 50,000 miles* you can fly to Australia
Booking period: 19th October 2017 2017 to 17th November 2017
Travel period: 19th October 2017 to 28th March 2018
This is how you book your award flight:
Check the route network of Etihad Airways and the miles needed to book your award flights.
Award flights can only be booked by phone under our special hotline +49 69 15 32 53 484**. You can reach our hotline Mondays through Fridays, from 9am to 5pm and on Saturday, 21 October 2017 from 9am to 5pm.
Call us to find out if your flight is still available and book your award flight.
The corresponding mileage will be deducted from your topbonus account after successfull booking.
*one-way award flight with Etihad Airways in the Economy Class, plus taxes, charges and fuel surcharge. Bookable subject to availability.
**award flights can only be booked under the above-stated telephone number. (German landline calls at local)