Sure you can, but if your surgeon has told you you can't, he or she may be making incisions in places where other surgeons among us would not!
The scars in front of the ears are visible because of their location, and surgeons differ in their incisional choices here. They fade over time, and depending on technique and attention to detail, can be truly insignificant. The earlobe attachment is the next area of concern--surgeons who try to suspend the cheek tissues from the earlobe cause "pixie ears" that are pulled down and forward, often with a widened white scar in front of the earlobe. (BAD) There are techniques to avoid this, but they only work if your surgeon chooses to use them.
Then there are the scars behind the ears! These are likely the ones that might inhibit your wearing a ponytail. If your surgeon makes an incision across the bare area of the mastoid skin and along the scalp line, this scar is not only visible but quite unsightly, and in need of hairstyles that cover this region. Surgeons who use this incision tell their patients that this is "necessary" to "get the neck right" and justify this tell-tale sign of facelift with this statement. Perhaps that is their training or habit, but those of us who choose a better incision placement along the backside of the ear high enough to cross the bare skin behind the ear at the level of the fossa triangularis (upper third of the ear where the pinna covers this skin), and from here into the scalp, will have NO visible scar. Closure technique is important for this incision to "work," as "notching" of the hairline needs to be avoided, and the incision should be beveled to avoid damage to hair follicles so there is not a bare area within the scalp either. Suture choice and tightness of closure are additional issues to be addressed by the careful and experienced surgeon!
No ponytail after facelift? Norm? Perhaps. Necessary? Absolutely NOT!