If we accept the top 4 of the AFC are in some order; Pittsburgh, Baltimore, New England, and Houston. The Bengals are essentially in a race with the Steelers, Ravens, Jets and Bills for three spots.
Of those teams, the Jets are done with their games against the top four, the Ravens and Steelers play the Bengals and no one else. The Steelers have 2 "tough" games left, Bengals and Niners. The Ravens have three tough games left, Bengals *2 and Niners, the Jets have 0 games against the top of the conference as the toughest opponents left are Philly?, the Giants, and hosting Buffalo, and the Bengals still have 4 games against the top teams in the conference.
This isn't saying the Bengals can't beat these teams, but even if they're as good as the opponents, they'll still probably be 2-2 in that stretch. If I were a betting man, I'd say the AFC playoffs are likely to be New England, Houston, Pittsburgh/Baltimore, Oakland, Baltimore/Pittsburgh, and the Jets once again coming in as the 6th seed.
I hope they prove me wrong.