I’m not sure whether doing it one way or the other would change anything significant (in terms of cost, anyway).
If the room is an office, you put receptacles on any wall wider than two feet, and place them so that no point along a wall is more than 6 feet from a receptacle. You can do that in a garage also.
If the room is a garage, you don’t need that many receptacles, but the HO will probably want them anyway. The only difference here is that they must be GFCI protected.
The room is not a bedroom, so it doesn’t need AFCI. It is not a dining room, kitchen, living room, etc., so it doesn’t need to be included in the SA circuits.
My suggestion is that you price (and install) the job with two 20 amp circuits, with receptacles spaced as though it were an office, and with GFCI protection for all receptacles.
If you are asking about the bare minimum to comply with code, then I tend to agree with Dale, but with one slight change. I would call it an office if (1) The garage door is gone AND (2) The floor is finished (carpet or tile or whatever). I would call it a garage if the garage door is still there, or if the floor is unfinished (i.e., just concrete).