I have come increasingly to view Walking on Air more as a book of inspirational and motivational poems rather than a set of interpretations of the cards of the Tarot. People who have read the book have passed comments on to me which have prompted this view. The poems are inspired by the Tarot but do not have to be combined with it in order for them to work their magic.
On the other hand the poems do work well when one is doing a reading. I have found that sometimes a poem will prompt a new insight into a spread when its meaning is not clear.
Any time one reads a poem, especially a poem such as these, it opens a portal into the inner world where you can discover more of yourself. The Tarot does the same thing.