Home Postcodes by state VIC 3720 Postcode 3720 3720 is the postcode for Bonnie Doon, VIC. Localities with postcode 3720Bonnie DoonVIC Postcode 3720 State or territory Victoria (VIC) Localities 1 Council area Mansfield Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 3719 · Postcode 3722