interesting....honey Bunch was the heroine of a series of books put out be the Stratemeyer Syndicate (Nancy Drew, Hardy Boys, Bobbsey Twins, etc.) from 1923 to the mid-1950s. The early promos said "Honey Bunch is a dainty thoughtful little girl and to know her is to take her to your heart at once."
That suggests it was a well-known term by then. There was a fad for such names in the twenties--things like Enna Jettick shoes. One source dates honeybunch to 1900-05.
I found it in a 1920 short story
Indeed he rather liked having her call him a perfect darling, an angel ,an old sweetheart, a precious, a honey bunch, and the other nice and deserved little names which rippled so spontaneously and with such enthusiasm from her lips.