关于德铁City-Ticket

大家好，我想请教一个city-ticket的问题.DB官网上对这种票的使用条件是这么描述的：
Travel on public transport for free after your rail journey – using your intercity ticket with BahnCard discount or your BahnCard 100. With City-Ticket you can travel for free in over 100 cities in Germany by bus, suburban train, tram or underground from the destination station to your destination in the city. On both your outward and return journey. The only condition is that you buy a ticket with a BahnCard discount, the destination station for your train journey is over 100 kilometres away and your destination lies within an area covered by City-Tickets. ACity-Ticket does not cost you a cent more and is automatically included on your DB rail ticket for journeys to participating cities. The City-Ticket eligibility is indicated by the suffix “+City” after the station name.
比如说，我买了Berlin-Hamburg的ICE，上面显示 Hamburg+City，那么是不是就是说到了汉堡以后可以免费坐车去我的目的地？是仅此一次单程票免费，还是比如我到了汉堡的A地，紧接着又去了B地，那么A到B是否还是免费？另外我在柏林的时候，去柏林火车站的那段车票是否也免费呢？
多谢楼主！