Does "Property Law" include "Intellectual Property Law" or are the two areas separate?

They are separate, and largely different forms of law. Most of what is commonly referred to as "property law" deals with what is called real property; real estate, land, etc.   However, it does have some aspects of dealing with tangible personal property (which also overlaps with tort and criminal law)

Protecting Intellectual Property Rights

Intellectual property is a significantly different form of law drawing on other areas (notably unfair competition law, especially for trademarks; law of agency; business law; etc.) but is fundamentally its own "thing."

A notable example of the difference is the phrase "Possession is 9/10ths of the law." This may be true in property law, where a possessor has superior rights to most everybody but the true owner. However, it would fall flat in IP, where your status as the legal rightsholder is the most important question.