'Pawn Power' is divided into three parts: 'The Elements of Pawn Play', 'Pawns and Pieces', and 'Pawn Power in the Game'. The first part, the 'Elements', presents the basic formations of Pawns that can arise during the course of a game: passed, isolated, backward, doubled, chained, etc. Unfortunately, Kmoch introduced an entirely new terminology that obscures his explanation and that renders his exposition meaningless without a guide to translation. For example,
'Helpers and sentries neutralize each other if there is a helper for every sentry. A half-free Pawn with inadequate help is no true candidate, but a faker.' (p.6) 'An unfree Pawn or a faker may suddenly become a passer of decisive power by means of a sacrificial combination. We call such a Pawn a sneaker.' (p.8) And much more of the same.
Chessville.com has just such a guide: Glossary of Terms 'Pawn Power in Chess'. If you manage to cut through the jargon, which was never adopted by other chess writers, you will see that his catalog of Pawn structures is comprehensive and applies equally to chess960.
The second part, 'Pawns and Pieces', presents specific characteristics of Pawn structures that enhance or reduce the powers of the Bishop, the Knight, and the Rook, with one chapter on each of the three pieces. For example, Bishops are affected by masses of Pawns on the same color or the opposite color that the Bishop moves; Knights prefer outposts where they can't be harrassed by enemy Pawns; Rooks work best on open files. This again applies equally to chess960, although Kmoch's examples are naturally drawn from positions in traditional chess (SP518 RNBQKBNR) where the specific opening is usually discernible in the position.
A further chapter, 'The Sealer and the Sweeper', deals with Pawn moves that close and open the position. I can't remember seeing any of this sort of action in any chess960 games, but there is nothing inherent to chess960 that excludes it from taking place. The last chapter in part two, 'The Center and the Fork Trick', is about a specific tactic that occurs in traditional chess, usually from 1.e4 openings.
The third part, 'Pawn Power in the Game', is about common formations that arise in the opening of traditional chess. About 60 pages, representing 20% of the book, deal with Benoni formations. I doubt there is much here that applies to chess960.
A web search on 'Pawn Power in Chess' returns reviews of more recent books in the same genre, for example Understanding Pawn Play in Chess on JeremySilman.com. While I haven't read any of these other books, I wouldn't be surprised to find that their content is just as relevant to chess960 as Kmoch's opus: 50% exclusive to traditional chess, 50% generic to chess960. This is still a higher percentage than most chess books, especially books on the opening, which are 100% exclusive to traditional chess.