Christoph,
The camp at Bonn-Hardthöhe/Hardtberg was liberated by the 1st Infantry Division between 7 and 10 March 1945, not April. This action eliminated German resistance west of the Rhine in the First Army area of operations.
Of course
The 46th Tank Battalion was organic to the 13th Armored Division. Any task force of an armored division was made up of the combined arms. To clairfy, this means the liberators of Rösrath: Stalag VI G Arb-Kdo 281 included units of the division other than the 46th Tank Battalion. Any attempt to determine the specifics of the liberation would require an examination of the reports and journals of those units, as well as the 46th Tank Battalion, and the combat command to which it was attached. Since CCB was refitting and reorganizing in the Dunnwald area on 11-12 April, the liberating parent unit was most likely CCA.
I've found my information here:
History of the 46th Tank Battalion
For me it is not so clear whether the 67th Armored Infantry Battalion or the 46th Tank Battalion lost its A, B and D company and whether Task Force Sheffy and Task Force Feldman were parts of Taskforce Delnore or separate Taskforces. And I'm also not sure whether this is caused by the quality of the text or by my English.
Christoph