Geesh, it's such a shame she can't just let go and be happy with you. Her comment about not letting her know prior about wanting to take a bath with her make me think of something though....hope this doesn't take the joy out of it for you too.
As our C suggested to my H...sometimes he has to conciously put things aside in order to be "intimate" with me. Perhaps, just perhaps, your W is like this as well. Maybe she really does need a bit of a "heads-up" in order to mentally prepare to be intimate with you. It's a frustrating thing true enough, but some people need this heads-up to de-clutter their brain enough to enjoy themselves. Don't know that your W is truly this way, just a thought.
Perhaps you could just ask her if she is someone who really does need a bit of a heads-up. I know that can just blow spontenaiety all to he**, but would you rather have a nice evening soaking in the tub with her that was pre-planned, and something you could look forward to....or another let down like last night?
As for her comment about "acting like you're rich"...going out and celebrating a raise, once, is not acting like you're rich, that's why it's a celebration....DUH! I feel like her comment was just a guilt trip about money, it was selfish and insensitive. On that, I believe I would have said something.