Wiktionary says these terms refer to "the opposite" side, etc and offers no antonyms.

But in practice, in the field of north vs south hemispheres, they are only ever used in my experience to refer to the southern hemisphere from the point of view of the northern hemisphere?

What terms should be used to refer to this aspect "oppositeness" of the northern hemisphere from the POV of the southern hemisphere.

Can I as an Australian refer to somebody from the northern hemisphere as "antipodean"? And even if technically correct will anybody understand me?

Or do the terms in this set have accepted antonyms?

Or what other solutions might I use when I want to convey this reversed point of view?