That one is a little tricky to analyze, but I believe that is a unity gain stage (no voltage gain, but capable of driving additional current to maintain the 1:1 voltage output with a low impedance load).
The opamp will drive the output to maintain 0V between the non-inverting and inverting inputs. While there is a 10K resistor in the feedback path between the output of the push-pull amplifier and the inverting input, at DC there is no current flowing through that resistor so it can be ignored from a gain perspective.
C5 forms part of an RC filter to prevent oscillation with the power output stage and to limit the high frequency response of the amplifier.
