I have left trees in bunkers on occasion, usually because there is some prohibition on taking them out, as mentioned above. One was the 12th hole at the Legend Course at Giant's Ridge, where the permit was contingent on not taking out any "ancient red pines." Looking back, not sure why I felt both bunker and tree were necessary, other than it was a slightly different look, so why not.
The inherent problem is trees are often very sensitive to changes in environment and grade changes in their root zone. That tree didn't last long. Over the years, many others have suffered the same fate due to just irrigation changes. Others come down if they were protected from wind in the forest, but are now exposed, without the deeper root system to hold them up against the wind.
So, while I don't think its the worst conceived bunker ever neither the tree in the bunker or that one foot circlebit of turf is as practical as it should be to survive long term.