One of Adam's friends has the middle name "Moonchild" which is what Bastian names the Childlike Princess. The ultimate origin of the name is from Aleister Crowley.
Mr Young's car has the number plate S1D R4T which is Tardis backwards. Also David Tennant in a lead role.
Ad seen on a bus in London.
The security guard at the airbase is reading "American Gods", which happens to be another Amazon series adapted from a book written by Neil Gaiman.
The Shadwell and Newt characters are in the witchfinder army and parody Hopkins.
Crowley makes a reference to the Antichrist having his father's eyes.
The series title is a pun on that of the "Omen" and follows the adventures of a child Antichrist and his hell hound, which turns out not to be a rottweiler.