They indeed recline on the Enclave. I was testing out the rear entertainment system the other day while my wife was driving. You can either pull the smartslide lever or the strap that folds the seat down to recline the seat while sitting in the captain's chairs.
I prefer to say that only the front seats "recline". The second row seats provide two seat-back angles: one upright, and one tilted back just enough to appreciate the difference while dozing (or watching the DVD? I wouldn't know).
As I recall from a visit to a Saturn showroom, the second-row 60/40 split-bench seats behave the same way.