I installed Project 2007 in my existing winxp Office 2007 bottle last week on Crossover 9.1. I run Project daily, and have yet to run into any issues. I would award it a "Gold" rating, but do not have access to test Project Server integration, which I suspect won't work, since my Sharepoint access from the IE7 install in the same bottle doesn't work.
I strongly suggest running Project 2007 inside an existing Office 2007 bottle, since the products are designed from MS to run hand-in-hand. Also allows use of the "send to" feature from within Project to send to Outlook.