I first read this many years, and liked it, though I also misremembered it as having something to do with a potion that caused floating (which seems to be a conflation of Mary Poppins and a short story whose title evades me). In fact, it's a novel of social commentary and critique of English life, lightly wrapped in adventure and romance.
The introduction to my paperback edition says that George's early life is closely based on author Herbert George's, and he does seem to know the material well. The first section of the book is a sharp analysis of a system of social classes and habits largely decrepit and outdated. It's keenly observed, and it seems credible that Wells is speaking from experience.
The novel largely follows George as he wanders on the fringes of his uncle's ventures, helpful, but disdainful and often disinterested. It recounts his distraction from study and work, his failures in love, and the partial waste of a natural talent for engineering. It's all wrapped in social critique, with comments on the class system, socialism, politics, economics, and other topics.
All that sounds dull, but it's not. As I re-discovered when reading Ann Veronica (a mainstream novel that immediately followed Tono Bungay), Wells was an excellent writer, with a fine sense for character, and an ability to convey his social opinion without overburdening his narrative. The purpose of Tono Bungay is clearly to express concern about England's direction, but that doesn't stop it from being a very successful novel as well.
The ending of the novel is an interesting mix. Our hero comes through bruised but whole, but the future of the country seems less bright. The result is a sad and lonely feeling, but not entirely without hope.
Unlike Ann Veronica, the women in this book are two-dimensional. In fact, pretty much the only full characters are George and his uncle, but it works despite that. George's aunt, Susan, is a key figure who nonetheless gets short shrift. There's a brief mention at the end that deserved a lot more space, and I was disappointed that Wells didn't make more of her and her relationship with George. Instead, she's played mostly for comic relief, and I got the feeling that Wells considered but then abandoned a larger role for her. I wish he had followed through; she deserved more time, and it would have added an interesting element to George's personal life.
Overall, a very readable, interesting novel that deserves more attention.