This will get you your different date ranges in a single query.
Code:
SELECT
TC.[Customer ID],
IIF(DateDiff("d",T2.[Order Date],Now) < 90, T2.[Amount],0) AS [Less than 90],
IIF(DateDiff("d",T2.[Order Date],Now) BETWEEN 90 and 179, T2.[Amount],0) AS [Less than 180],
IIF(DateDiff("d",T2.[Order Date],Now) BETWEEN 180 and 359, T2.[Amount],0) AS [Less than 360],
... etc ...
FROM
tblCustomer AS TC
INNER JOIN
tblOrder as T2
ON TC.[Customer ID] = T2.[Customer ID];
Note that I have changed your table names, since ORDER is a reserved word. It's also best to avoid spaces in field names, but I've left those alone.