A spelling variation of Bentley, an Old English name referring to a meadow with bent grass. And since your little Bentlee will inevitably bring home more than his fair share of grass stains, this is a perfectly plausible name.
Ben, Benny, Lee.
Famous people named Bentlee:
There are currently no famous people with the "Bentlee" spelling.
This name, in whatever spelling, is now synonymous with the British luxury car brand Bentley.