The calculated distance (air line) between Heppenheim an der Bergstrasse and Bonn is approximately 102 miles respectively 164 kilometers.
By car or train, the actual journey to Bonn is certainly longer, as only the direct route (as the crow flies) between Heppenheim an der Bergstrasse and Bonn has been calculated here.
Air line (approximately)
164 kilometers
88 nautical miles