The 2002 code makes it clear that the cold water should be at a minimum be bonded and if 10' of metal in the ground shall be used as a grounding electrode.
250.50 requires that if available each item in 250.52(A)(1)-(6) shall be bonded together. Metal underground pipe is item 250.52(A)(1).
250.104 (A) requires bonding of metal water piping.
So any jurisdiction not using the cold water is violating the NEC. The workbook notes in 250.52(A)(1) that there has always been uncertainty about using the cold water, but that NIST has monitored the issue and found minimal problems.
