Top-tier elite members of airberlin topbonus now have two new benefits. Members of topbonus Gold will receive priority on the waiting list at the airport when booked in flex-tariff class and Gold members receive a booking guarantee, up to 48 hours prior to departure. The guarantee is valid on all flex-tariff flights booked via the topbonus Gold hotline. Priority waitlist and the booking guarantee are offered in addition to 40 percent bonus miles, non-expiring miles and other benefits given exclusively to Gold members.