Yes, it isn't killing the infection.
The recommended treatment for an inner ear infection is either clorpalm or both baytril + clavamox
plus an anti-inflamatory to help prevent permanent damange.
If she still has an infection I would suggest you try clorpalm, if that doesn't work there is another antibiotic you can try.
I would keep her on the antibiotis twice a day for at least 4 weeks if the meds seem to be helping.
Miriam had an inner ear infection that took about 9- 11 months to get rid of ...
The usual antibiotics seemed to keep it somewhat under control but then after 6 - 8 weeks on the antibiotics, I would stop the meds and her head tilt would again worsen. At this point she has been off antibiotis for about five months so the infection seems to be gone.