Bucks County council provides a call centre and a web portal for reporting hazards and potholes (http://www.transportforbucks.net/BCC-report-a-problem.aspx). From our experience they react reasonably fast. However their criteria for evaluating which potholes to cover are very strict leaving the road surface still hazardous for cyclist. Moreover the quality of the repairs seems to have deteriorated significantly as the potholes reopen shortly after the work is done.
One can view all reported problems that have been accepted by BCC in an interactive map (http://www.transportforbucks.net/BCC-report-a-problem.aspx). Interesting to note that although bridleways and footpaths are marked, Cycle routes are not.

Potholes in Wendover