Property getters are not simple functions. Class methods have first a reference to the class instance (Self) which the compiler needs before it can determine the address of the method in question (a different instance of the same class would have methods at different addresses in memory).
The property keyword does not declare a variable. Properties are not variables but a syntax extension to the original Pascal, a form of indirection giving controlled access to normally inaccessible routines or variables. However in the simple case that a property is an alias for a simple variable (a field somewhere in the class declaration) the @ operator can be used.
I fail to imagine a situation in which knowledge of the address of a private method is really useful, but perhaps such a situation arises for you.