Those vortices aren't being caused by the tailplane. If they were from the tailplane they'd be at the outboard end of the L & R tailplane ie similarly to a wingtip vortex, but opposite rotation
These ones can be seen to occur inboard near the fuselage, just as the smoke passes the flap. At that point higher pressure air from below the flap flows around the the inboard tip to the lower pressure air above. Same as a wingtip vortex, but the wing 'tip' is the inboard end of the flap.