Write SQL query to solve given problem: Which customer has the highest subtotal amount of sales orders whose assigned to the salesperson with the highest bonus?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T1.CustomerID FROM SalesOrderHeader AS T1 INNER JOIN SalesPerson AS T2 ON T1.SalesPersonID = T2.BusinessEntityID ORDER BY T1.SubTotal DESC LIMIT 1