The druid's Wild Shape feature says, in part (PHB, p. 66-67):
You can't cast spells. [...] You retain the benefit of any features from your class, race, or other source, and can use them if the new form is physically capable of doing so.
The relevant part of the Circle of the Shepherd druid's Spirit Totem feature says (XGtE, p. 23):
Starting at 2nd level, you gain the ability to call forth nature spirits and use them to influence the world around you. As a bonus action, you can magically summon an incorporeal spirit to a point you can see within 60 feet of you.
Can you use the Spirit Totem feature of the Circle of the Shepherd druid while you are in your Wild Shape form?
From what I can deduce, Spirit Totem would be available for a Druid to use in Wild Shape form because it is a class feature, not a spell (though it is magical).
I would appreciate any answers to support or contest this. If you or your table have play-tested this feature, even better!