Unfortunately, RootsMagic has never allowed a particular name to be associated with a particular fact/event. So to get the result you want, you have to go through some gyrations to use the husband’s surname. But then for the sentence to work for both the husband and the wife, you must also customize the sentence to be different depending on which person is the principal person, the male or the female.
Here is a sentence that should work in most cases:
<%Person%[Person:Given] and [Spouse:Given] ([Spouse:Surname]) [Person:Surname]<, [Person:Suffix]>|[Spouse:Given] and [Person:Given] ([Person:Surname]) [Spouse:Surname]<, [Spouse:Suffix]>> celebrated <[Desc]> <[Date]>< [PlaceDetails]>< [Place]>.
If you don’t want the wife’s maiden name to appear, you can omit the “([Spouse:Surname])” and “([Person:Surname])” parts of this sentence. Note that the anniversary being celebrated must be entered in the Desc field, for example, “their 50th wedding anniversary”.