On Java, you can apply Unbreaking, Mending, and Curse of Vanishing on a brush. However, you cannot apply those enchantments on a brush in Bedrock Edition.

Step to Reproduce
1. Get a brush.
2. Try to apply it using /enchant commands.
3. Also try to apply the enchantment with an anvil.

Observed Result
The game refuses or unable to apply the enchantments on a brush.

Expected Result
You should be able to apply Unbreaking, Mending, and Curse of Vanishing enchantment on a brush.