Gold is real money. At least, it’s as real as money ever gets. Gold represents wealth. It can be exchanged for wealth. And since the above-ground supply of gold grows about as fast as the economy itself, gold tends to hold its value over centuries. Today, gold is worth about the same as it was worth 2000 years ago.
FYI, Bonner is no Johnny-come-lately to the gold trade. He touted the idea of "buying gold on dips" as half of his trade of the decade for, well, the last decade.