Thank you for the new knowledge that "eso" is pronounced similar to "iso" in some dialects of English, I didn't know that.
However, the word "isoteric" is more correctly spelled (in non-phonetic spelling) as esoteric. The prefix "eso-" means "inside" in Greek, as in "esothermic", or "esophagus". The prefix "iso-" means "equal", as in "isomorphism", "isosceles", "isometric", etc.
However, the word "isoteric" is more correctly spelled (in non-phonetic spelling) as esoteric. The prefix "eso-" means "inside" in Greek, as in "esothermic", or "esophagus". The prefix "iso-" means "equal", as in "isomorphism", "isosceles", "isometric", etc.