The correct term is “additional bonding”. It should already have the branch circuit ground connected to the little green wire inside the furnace compartment so that is the basic bond that was ok for quite sometime.
Most areas around here started requiring the additional bonding in late 2007 with very strict enforcement. Separate permit required by an electrician in some areas when it first became an issue. Its more expensive to add when the distance from the gas pipe to the ground electrode is long. A second ground rod is not allowed, it must be bonded to the existing ground system for equipotential.
Upgrade recommended: No grounding or bonding found for the gas piping except through the furnace equipment’s ground. This is an accepted method in many areas but recent changes have occurred to the bonding requirements in some areas and upgrades are recommended to enhance the safety level of the home.
The CSST flexible gas piping that is used throughout the house is a common item. A class action lawsuit involved this type of product. The details are available at www.CSSTsettlement.com or 800 420-2916
The product was not recalled but recommendations were made to closely follow the manufactures installation instructions. The instructions are not part of this inspection but likely involve proper bonding methods of the pipe to prevent issues with lightning damaging the thin walled pipe. I recommend having upgraded bonding installed by a licensed electrician, plumber or HVAC person that is familiar with the installation instructions. Typical methods use a #6 solid copper conductor clamped to the black iron main gas pipe at the exterior with the other end clamped to the existing electrical grounding electrode conductor (GEC) that runs to an existing ufer grounding system or the existing grounding rod imbedded in the earth. Upgrade products called gas breakers can also be added inline with the gas piping distribution for a higher safety factor since they are designed to shut off if an unusual flow of gas is present.