Chickens do sneeze occaisonally if they are kept in a dusty enviroment, or eat too dusty of feed. However, if you notice more constant sneezing, or notice other respiratory symptoms like swelling of the face, discharge, and gurgling, your birds may have a respiratory disease. I'd start giving your birds some probiotics and electrolytes, just in case they are coming down with a respiratory disease.
Antibiotics can be used to treat respiratory diseases, but only work if the disease is bacterial. Because the disease that your birds are experiencing seems mild, its more likely that it is viral. All you can do for a viral disease is provide supportive treatment, like good feed, electrolytes, and warmth.
If any of your birds gets worse, isolate it from the flock. Give supportive care, and if that doesn't work, try the antibiotics. Otherwise, if your birds remain the same or if the sneezing disappears, they were probably fine.