Has anyone ever dug into the capacitance introduced by adding internal VCC / ground planes into a PC board and whether the capacitor formed by the two planes has a measurable value compared to that of the bypass capacitors normally placed on a given board?

Just curious.

 

Sure, the measured capacitance is typically in the pf range per square inch.
https://www.eeweb.com/calculate-the-capacitance-of-pcb-planes/

VCC / ground planes are normally designed to provide low impedance power paths and EM field reference points for signals (integrity, cross-talk, etc ...) on the board not as bypass capacitors.

 

Makes sense. Like I said, it was just idle curiosity. Thanks!

 

I worked on a project for a while where we measured the capacitance of each trace on a PCB to see if it was good. (looking for trace-trace shorts or opens) Board testing is done at the PCB factory.
Short thin traces have very low capacitance.