Are the PW1100G and PW1400G engine series not certified by the FAA?
They are certified by the FAA. The following 1100/1400 models:


  PW1133G-JM, PW1133GA-JM, PW1130G-JM, PW1129G-JM, PW1127G-JM, PW1127GA-JM, PW1127G1-JM, PW1124G-JM, PW1124G1-JM, PW1122G-JM,PW1431G-JM, PW1431GA-JM, PW1431GH-JM, PW1428G-JM, PW1428GA-JM, PW1428GH-JM


Are certified under TCDS (type certificate data sheet) E00087EN (PDF).

Note: The certificate holder is International Aero Engines, LLC, and I was able to find it by searching https://rgl.faa.gov for "E00087EN", which I got from the neo's TCDS.