CSST

CORRUGATED STAINLESS STEEL TUBING

One and two family dwellings and townhouses in Connecticut need comply with the 2012 IRC:
2012 ICC IRC

Section G2411
ELECTRICAL BONDING

G2411.1 Pipe and tubing other than CSST.
Each above-ground portion of a gas piping system other than corrugated stainless steel tubing (CSST), that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping, other than CSST, shall be considered to be bonded where it is connected to appliances that are connected to the equipment grounding conductor of the circuit supplying that appliance.

G2411.1.1 CSST
Corrugated stainless steel tubing (CSST) gas piping systems shall be bonded to the electrical service grounding electrode system. The bonding jumper shall connect to a metallic pipe or fitting between the point of delivery and the first downstream CSST fitting. The bonding jumper shall be not smaller than 6 AWG copper wire or equivalent. Gas piping systems that contain one or more segments of CSST shall be bonded in accordance with this section.

The 2014 NEC Section 250.104(B) has an Informational Note No. 2: Additional information for gas piping systems can be found in Section 7.13 of NFPA 54-2012, National Fuel Gas Code.
There is no difference in the requirements for other than 1 & 2 Family or Townhouses. Other dwellings, commercial and industrial buildings in Connecticut need comply with the 2012 NFPA 54:

2012 NFPA 54 NATIONAL FUEL GAS CODE
Chapter 7 Gas Piping Installation

7.13 Electrical Bonding and Grounding
7.13.2 CSST. CSST gas piping systems shall be bonded to the electrical service grounding electrode system. The bonding jumper shall connect to a metallic pipe or fitting between the point of delivery and the first downstream CSST fitting. The bonding jumper shall not be smaller than 6 AWG copper wire or equivalent. Gas piping systems that contain one or more segments of CSST shall be bonded in accordance with this section.

The 2015 IRC again has almost identical language to the NFPA on this subject. The 2017 NEC Informational Note refers to the 2015 NFPA 54. Our requirements will not change much for the future:

2015 NFPA 54
Chapter 7 Gas Piping Installation

7.13 Electrical Bonding and Grounding
7.13.1 Pipe and tubing other than CSST. Each above-ground portion of a gas piping system other than CSST, that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping, other than CSST, shall be considered to be bonded where it is connected to appliances that are connected to the equipment grounding conductor of the circuit supplying that appliance.
7.13.2 CSST.
CSST gas piping systems containing one or more segments of CSST, shall be bonded to the electrical service grounding electrode system or, where provided, lightning protection grounding electrode system.
7.13.2.1 The bonding jumper shall connect to a metallic pipe, pipe fitting, or CSST fitting.
7.13.2.2 The bonding jumper shall not be smaller than 6 AWG copper wire or equivalent.
7.13.2.3 The length of the jumper between the connection to the gas piping system and the grounding electrode system shall not exceed 75 feet. Any additional electrodes shall be bonded to the electrical service grounding electrode system or, where provided, lightning protection grounding electrode system.
7.13.2.4 Bonding connections shall be in accordance with NFPA 70, National Electrical Code.
7.13.2.5 Devices used for the bonding connection shall be listed for the application in accordance with ANSI/UL 467, Grounding and Bonding Equipment.

Bottom line:
Bond ALL aboveground gas piping systems containing any CSST tubing using a listed grounding clamp on the solid metal pipe or fitting portion of the gas piping system between the point of delivery and the first downstream CSST fitting directly to the service grounding electrode system with a minimum of 6 AWG copper wire bonding jumper. If NO CSST is used, the usual equipment grounding conductor is satisfactory