You'll get lounge access whether upgraded to a club floor room or not at Westin and Sheraton properties... provided that the lounge is open. Don't count on breakfast/cocktail/appetizer coupons if the lounge is closed (though some hotels provide this) because SPG T&C say that if the lounge is closed the hotel is treated as not having a lounge for benefit purposes.

As observed, 'Towers' are excluded from the benefit. And the benefit doesn't apply to other branded hotels.