From IBZ airport to Ibiza Town it’s roughly a 10-15 minute drive; getting to Sant Antoni or the north of the island takes considerably longer. Public buses connect the airport to the main towns, at a fraction of a taxi’s cost.
For accommodation further out, especially in the quieter north, a pre-booked private transfer is usually simpler than combining bus and taxi — particularly useful for late-night arrivals when public transport has stopped for the day.
Taxis have a posted fixed fare to the main tourist zones — confirm the price before you get in, especially for longer trips.