It is not mandatory to leave a tip in bars and restaurants; however, it is advisable to do so if you have felt that the place has met your expectations. Leaving a tip or a bonus signifies that you have been comfortable in Menorca and want the business to prosper.
This money will go directly to the staff that has treated you and encourage them to continue treating you great. Also, on the other hand, you will receive a friendly smile from the waiter.
Leaving a tip is essential in a good restaurant; in post-covid times, many waiters are underpaid. Giving them a tip, you help them have a significant extra money. Day-to-day prices have risen, but salaries remain generally stagnant at restaurants.