The more I think about Bowman's objection regarding NWT treatment of epi for Rev. 5:10, the less sense his objection makes. Nouns are classically defined as parts of speech that name persons, places or things. So we're to believe that epi (in some cases) can be rendered/understood as "over" when it comes to persons (Revelation 17:18) or things (Acts 8:27), but it cannot be so understood when referring to places? Who made this rule and which grammar states it?
Another question for Dr. Bowman would be, is Egypt a place-noun? If he concedes that the noun does name a place, I would draw Bowman's attention to Genesis 41:41:
εἶπεν δὲ Φαραω τῷ Ιωσηφ ἰδοὺ καθίστημί σε σήμερον ἐπὶ πάσης γῆς Αἰγύπτου
Examples have already been provided to show that epi ths ghs also can be rendered "over the earth."