There is no Engineering Trainer, Goblin Engineering Trainer, or Gnomish Engineering Trainer that has the quest to begin the Goblin Engineer specialization. No trainer in a major city, no goblin in Gadgetzan, Ratchet, Everlook, or the random new neutral goblin areas have the quest. The only way to start the quest for Gnomish Engineering is to go the the Gnomish Engineering Trainer in Tinker Town, Ironforge. If I want to get Goblin Engineering I'd have to become a Gnomish Engineer and then swap specializations.
Apparently I become a Gnomish Engineer at some point which I don't ever remember cuz I leveled the profession in Wrath when there wasn't really a reason to even get a specialization and when I checked none of the Gnomish Engineering Trainers had stuff I could learn. It wasn't that there was nothing on the list it was that everything was on the list but I was unable to learn any of it because it said I didn't have Gnomish Engineering.
Anyway, I used the book, unlearned Gnomish, and used the book to learn Goblin. Thanks for the help.
Wrath reason for specialization: Ammunition varied at tier 10 content (goblin had bullets, gnomish had arrows)
Cata reason for specialization: MOAR pets!
note: Lunar festival recipes can require both signature "goblin rocket fuel" and "inlaid mithril cylinder" for same pattern /facepalm