go a bundle on be very keen on or fond of. British informal
☞ In this idiom, bundle is being used in the late 19th-century US slang sense of a bundle of money, i.e. a large sum. To go a bundle on was originally early 20th-century slang for betting a large sum of money on a horse.
1968Adam DimentBang Bang Birds I don't go a bundle on being told I'm a pro.