City ticket included for the validity of German IC trains

Yes, because "tarifliche Gleichstellung" (grouping of stations) is applied. In this case, you get a ticket that does not have the name of a specific station as a starting or ending point, but the name of a group of stations. You can see that this applies to your case because the starting point appears as "Bremen" (the name of a group of stations) instead of "Bremen Hbf" (the name of a specific station). Therefore, you can start your journey at all stations of the Bremen station group, which you can find on pages 7 and 8 of this list in the penultimate column. In the case of Bremen, the station group goes as far north as Bremen-Farge.

Explained differently, the grouping of stations means that for long-distance tickets (> 100 km) all stations in certain sets of stations are treated as if they were identical. Regulations for station groups are found in this PDF in Section 3.7.

As Tor-Einar mentioned, the City-Ticket option often also allows you to travel to your starting point. However, there are some important differences:

  • City-Ticket is valid for all public transport, with the grouping of stations you must use only trains.
  • City-Ticket is not included in the super savings rates (Super Sparpreis), the grouping of stations itself.
  • City-Ticket is available only in approximately 130 cities, the grouping of stations also exists in many other smaller cities and towns, some of which have only a few thousand inhabitants.
  • The covered area may be different. City-Ticket is generally valid in some specific areas of local public transport (current list), while for the grouping of stations a different list of stations applies.
  • City-Ticket is indicated by the explicit marker "+ City", the grouping of stations is visible by using the name of a group of stations. However, the latter may be difficult to notice because there are cases in which the name of a group of stations is the same as the name of an existing station (for example, "Hamburg-Harburg"), in which case you must verify the Travel distance to find out if the grouping of stations applies to your ticket.