Is there a fee for a spouse

You got a very detailed answer! More details than I know... And I do know they change. Now they scan your ticket at the door.

I paid $29 for my Mother, i have Delta Reserve cc

MEMBERSHIP LEVEL OR CUSTOMER CATEGORY NUMBER OF GUESTS Delta Sky Club Executive Membership Complimentary - Two guests, or spouse/domestic partner and children under 21; Plus two additional guests for $29 per guest per club visit Delta Sky Club Individual Membership Two guests or spouse/domestic partner and children under 21 for $29 per guest per club visit Delta One or Delta SkyTeam Premium Cabin Passenger None Delta Reserve Credit Card Member Two guests or spouse/domestic partner and children under 21 for a discounted fee SkyTeam Elite Plus (Delta Diamond, Platinum or Gold Medallion)* One guest Single Visit Pass  None

Usually $29 but depends on what type of membership you have.