I'd say Bundy was INFJ, not ENFJ or ENTP.
It's clear for me that he was no P. He was such a planner, extremely careful with the way he executed his crimes. It has nothing to do with the live-in-the-moment, impulsive ways of an ESTP. Also his response to that girl's rejection ("Stay calm, be patient, and plan revenge") sounds quite J to me - in fact it's the stereotype of the wounded INFJ angry with the world. Descriptions of him (quiet, private) put me more in mind of an introvert (though that isn't conclusive at all).
The Ni-Fe-Se combination is the best to figure people out and manipulate them, as he was doing with those girls. Inferior Se can notice all the small details in a person's appearance and behaviour (this is a mostly inconcious process however) and the dominant Ni will take all of this and put it together so as to form an accurate global picture of the person. Fe permits to understand people's feelings, and really to manipulate these feelings.
Ni-Fe-Se is also very useful to blend in in society or quickly adapt in a different social context, because it permits to 1) be aware of all the rules and expectations (Fe-Se), 2) form a picture in your head (Ni) and 3) project a fully formed image of yourself to the world (Ni-Fe). Ted Bundy was described by everyone as an extremely charming guy, a former good and intelligent student with a future in politics, whom nobody ever suspected capable of such horrible crimes (lots of people couldn't even believe it at first). This show how good he was at controlling how people viewed him.
I don't think he was ENFJ, because Ti doesn't sound at all like his inferior function. The easy way he used it to argue his point (or perhaps see the flaws in a plan, or think quickly of an escape, I don't know) would make me put it as his tertiary function, in a supportive role (for example I think he used Ti a lot in that last video we have of him, where he explained how pornography was what pushed him to do what he did). It makes more sense for Se to be his shadow, I think. INFJ, when unstable, have a tendency to fall back to their inferior Se, having ESTP moments. But as their Se is undeveloped (their weak point), it often takes the form of a more or less unhealthy ESTP, sensation seeking in a rather uncontrolled manner. It fits with the nature of Ted's crimes, all about lust. That monster inside him would be his shadow.