It seems very easy to do it from Mallorca, but it is somewhat more expensive if you want to get there from Ibiza. Since there are rarely direct flights between the two islands, read on to discover possible ways.
Iberia (Air Nostrum) covers this route. It is a flight that usually operates on Sundays and a specific day during the week. You should know that you will only find it in summer since it is not worth having a direct flight in winter.
If there is no direct flight, you will have to make a stopover at Palma Airport. The goal is to reduce the scale time as much as possible. In this case, we will have many more airlines offering this alternative route (Air Europa).
It is the slowest option, but we will have the advantage of bringing your car. To do this, you will have to take a ferry from Ibiza to Palma de Mallorca, cross the whole of Mallorca by car, and take another ferry from Alcúdia to Ciutadella. Balearia is a company that usually has more frequencies.
Another option, but less common, is to take the Transmediterrania shipping company that sometimes covers the Palma-Mahón route. You will have to look for the most economical choice, and at the same time, it adapts to your schedules.
Given that Ibiza and Menorca are very touristic islands, it is not surprising. You can see that on the weekly frequencies that connect both islands of the Archipelago.