I’m afraid retrieving country codes cannot be done in one search request yet, see MBS-6741.
The only solution so far is to make additional lookup requests with inc=area-rels until retrieving area’s country.
For example, in your example request, your first result is the place Bikini Test the area of which is La Chaux-de-Fonds. Use its area MBID to make lookup request for parent area:
It returns every part of Neuchâtel and its parent area (type-id is "de7cc874-8b1b-3a05-8272-f3834c968fb7"and direction is "backward") Switzerland (with iso-3166-1 code CH).
@yvanzo thanks a lot
one final question - what if I want to search for multiple type on the ‘place’ entity i cannot work it out
eg.
type=studio OR type=venue