Bonus is related to Advantage. Advantage is related to Gain. Gain is a synonym of Mushroom. 
Favorable is a synonym of Encouraging. Incentive is a type of Encouraging. Incentive is a synonym of Bonus. 
Bonus <--RelatedTo--> Advantage <--RelatedTo--> Gain <--Synonym--> Mushroom 
Favorable <--Synonym--> Encouraging <--IsA-- Incentive <--Synonym--> Bonus 