I tried the "Vintner's Tasting Menu" while I was there last week, and I'm guessing that's what you are referring to. I ordered it just like any other menu item, I didn't have to do anything in advance. It was $60 for four courses. For another $30 or so there's a wine course that goes with it (I didn't spring for that so can't comment). The food was interesting and very good. But I would say it's overpriced compared to similar meals I've had elsewhere (but then, $60 is probably overpriced for any meal). At a French restaurant I enjoy back at home, the tasting menu is around $40 for 4 courses. The waiter is also very nice and explains each dish in detail, and the atmosphere seems cozy and intimate. The Napa Rose is just too big to have such an atmosphere - it seems "busy". Also, the waiter was trying to upsell us at every occasion, which I found quite annoying considering how much we were shelling out already. With a different waiter and maybe at a later hour when there are fewer families with kids (we ate at 6:00p), it might be totally different. Other entrees on the menu range from $20-$35 with appetizers around $10-$15. My wife had a couple of these (which were very good) so not everyone in the party has to get the tasting menu. I'm guessing the main draw here is the wine list, but I don't drink wine so I can't comment on how the experience would be with that - other than a lot more expensive.
The Vineyard is an alternative that I'll try next time and you might want to look into. They are only open Fri-Sun. The menu listed a 3-course meal for around $40 and this might be comparable to the Napa Rose's "tasting menu". There's also a 4-course meal four a bit over $50 if I remember correctly. I think they also have a large wine selection if that's what you're looking for.
If you have kids, Pinnochio's Workshop is the "daycare" place at the GC and is just around the corner from Napa Rose (and probably close to the Vineyard as well). My daughter is usually apprehensive about daycare places, but after a few minutes of seeing all the things to do, she decided to stay. When we returned to pick her up after our meal, she wanted to stay longer. It's $13/hour plus an optional $5 for dinner.