Definition of a bunny hop
I see that the definition of a bunny hop is subject to the kind of cycling we're talking about. I doubt you'll find a specific definition that everyone will agree with. 

However, what's common with (almost) everyone's concept of a bunny hop is that the front wheel elevates first and and the rear follows — just like a bunny hops — front paws first. Whether you and your bike are airborne due to clip pedals, upward pull from the handlebar or black magic, doesn't matter in my opinnion.

Where my definition came from? 20 years of BMX, urban and dirt biking, occasional downhill and aggressive trails. Last 5 years mostly just commuting with a cyclocross. Still feels good to bunny hop over curbs and branches.