Hi Mike,
"Bookmatching" might not be the best word, though I haven't seen it described any other way in this particular context.
The idea here is that strips are used in the same sequence they were cut from the board and with the same longitudinal alignment. The effect is subtle because the strips tend to be narrow, but you can see a repetition in the grain pattern that gradually morphs across strips.
Sometimes these strips are laid out as "true" bookmatched pairs (rotating every other strip), sometimes not.
I have have seen builders use wide book matched panels for relatively flat areas, and in some cases the builder rips these panels into strips to allow them to conform to a curve while (mostly) maintaining the flow of the grain. This is probably what most woodworkers think of as bookmatching.
Anyone out there have another term to use here?
Patrick