For your car, the engine and transmission are controlled by the PCM so you only need 1 V1 PCM license (for the Duramax LB7/LLYs you'd need 2, 1 for the ECM and 1 for the Allison TCM). But down the road, if you want to tune a vehicle that has both an ECM and TCM, you'll have to use 2 licenses with a V1 vs 1 with a V2.
Id look at it like this: Do you want to use EFILive on any other vehicle besides your Camaro, now or in the future? If the answer is yes, then a V2 upgrade might not be a bad idea to future-proof yourself. If it is no, then buy a V1 Commercial upgrade and a V1 license and be on your merry way.