I have to use he miles earned by business travel for business travel (but not the additional 25% I get from my status, since this was not earned by business travel).
I do no want to push the issues with hotel points, since I pay the difference between the 80 EUR I am allowed to spent and that what I pay for a nice hotel (sic) out of my own pocket.
By the way, LH has an agreement with the local tax authorities for that what's called "geldwertervorteil", so that the Germans have not to pay taxes for this.