I am a member of REBAC (Real Estate Buyer's Agent Council) and an Accredited Buyer Agent.
Your question is asking from one point of view, i.e. does each "technically" need a license.
I believe a better point of view is, "What does the buyer think?"
If the buyer in this case goes out with the couple, and asks questions, even seemingly innocuous ones like "what do you think of this bathroom?" or "what's this neighborhood like?", the buyer may in fact believe that BOTH parties are his agent. This can create an "implied agency" even when none is intended.
Succinctly, agency may be referred to as the relationship between a principal and an agent whereby the principal, expressly or impliedly, authorizes the agent to work under his control and on his behalf.
It would seem to me that the licensed agent would be taking on EXTREME risk by working alongside an untrained, unlicensed spouse. "Small talk", as you call it, can be full of some of the biggest bombshells, and are a way of passing information relied on by the client. Further, what the client reveals to his agent may be of a sensitive nature, not to be shared with someone untethered by the constraints of fiduciary duty. Besides, it's JUST NOT PROFESSIONAL.
For the best representation of the client, for the safety of the licensee, and for the betterment of the industry as a whole, the licensed/unlicensed (husband/wife) combo is a no-no.
The Bremner Group at Coldwell Banker
REALTOR, 00588885, ABR, CDPE, eAgent, CSP, SFR, HRC, CRE
(O) 310-571-1364 DIRECT