I have a brand new home in Baja & 11 sinks in home, H2S gas coming from only 1 Cold water faucet in master bath, all PVC pipes?

I don't believe that it's
Hydrogen sulfide in your water system, (city water or a pump?).
If it were you would have it in all cold water faucets. Sounds like bacteria to me. Try this; Remove the aerator and soak it in bleach.
If the water still smells with the aerator removed then shut the water off, remove the cartridge and soak it in bleach also.
Now turn the water back on for a minute to flush out the supplies. The water should no be smelly. If it is let me know, Good luck, Tom