> On my bill (ISO-NE region/market) there is a separate generation and transmission fee.
Same here, on the Peninsula of the Bay Area: Generation comes from generation owned or contracted by SVCE [0], which is then delivered via PG&E (both transmission and distribution).
Billing is handled by PG&E: My bill has a section for PG&E charges, and a section for SVCE charges. The PG&E section has a generation credit, that effectively removes any costs of non-SVCE power generation, leaving the costs of transmission & distribution.