Was taking a look at the BMF touring forum yesterday, and there's a link to the German FJR website
http://www.fjr-tourer.de/.
One of their web pages has links to biker friendly hotels that might be sponsors for their meetings, or partners to the German bike touring club. Or possibly something else

German's not my strong point.
You can find it by clicking on the FJR logo on their home page, then clicking on "Sponsoren Hotels" in the list on the extreme left.
We regularly stay in Ibis hotels, and have no complaints, but like a lot of chains they can be a bit impersonal. Another alternative for the French bit of your trip is the
Logis de France . They are independantly owned and can be really good value. The ones we've stayed at have been excellent.