Saudi Arabian forces launched air strikes on Yemen a month ago to stop advances from the Shiite Houthi rebels.
Prince Talal, who owns $300 million stake in Twitter, apparently made the pledge on social media but the post has since been deleted, the International Business Times reported.
He wrote: "To recognise the one hundred participating Saudi pilots I am pleased to present them with 100 Bentley cars,"
Bin Talal, 60, is the grandson of Saudi Arabia's founder Ibn Saud and one of the richest men in the world.