The thing I didn't realize about this book is that's it meant to be an inspirational. At least for some values of inspirational. The hero and heroine are Catholic, and they have sex after they're legally married but before they're married in church. It's not heavy-handed for the most part; the hero, Siegfried, has abandoned his faith after the horrors of war and reclaims it, so far as I can tell, mainly because he falls in love with his wife, and then has a near-death experience. The heroine, Alice's, faith issues seem to be more social class issues to me; her mother ran a brothel in San Francisco, and Alice tries to hide it; her acceptance of her mother is sort of faith-related, I suppose, but the link is not direct in the story.
They're trying to save a winery on the brink of ruin, and survival might depend on getting a contract to make sacramental wine. The historical details, especially the winemaking/Prohibition neep, were really cool. I wanted more winemaking neep, in fact. The story devoured me up until a series of Big Misunderstandings; donning my romance-colored glasses, I was able to endure that back-and-forth until the classic moment of "character almost dies." The near-death sort-of return to faith thing felt a bit awkward and diminished my opinion of the book. I wasn't horribly annoyed by it, it was just awkward and I wished it hadn't been so classic. But after that, I was satisfied by the happy ending (possibly too sweet a happy ending for some of you).
So, I recommend with the caveats above.