Vegan Friendly in Santa Monica w/good wine list
I didn't have a good experience at La Cachette the one time I went (for a business lunch); to be fair, I didn't stick to the known vegan entrees, but asked them to do the truffle risotto vegan style; the result wasn't that great IMO, and the after-effects made me wonder if there were perhaps non-vegan ingredients somewhere in there. Anyway, to my mind, not worth the money (even on someone else's dime), at least based on my one experience there.
I'd be tempted to say Grace over Mélisse, unless you really like the whole froth trend... The only time I went to Mélisse was the day before Valentine's day, so maybe it wasn't up to par (I did give them advance notice I was vegan, but I'm sure the kitchen was extra crazy that night), but I just wasn't blown away. I was pretty impressed with Grace; my entree wasn't amazing, but it was at least inventive, and the beet salad was really good.
Inn of the 7th Ray is another good choice - even my way-non-veg dad liked the vegan mock duck. Madeleine Bistro might be good if you're ok with an entirely vegan place; wine list is at least so-so IIRC. But neither is super close.
I don't think the RFD in Santa Monica serves wine still... but the West Hollywood does (I don't think their wine list is anything to write home about but they have some decent wines for a fair price). As someone else said - maybe good for lunch or something.
Head out to Inn of the Seventh Ray in Malibu.
Second La Cachette, and if you'd venture over to the city, Grace will accommodate you if you call as well.
Middle of the road, I think Fritto Misto and i Cugini could work. Mao's Chinese Kitchen down in Venice is another great option. 26 Beach and Houston's both have excellent veggie burgers. The Firehouse also can accommodate. I know none of these are high-end, but these people gotta eat at other times in the day too :-)
Not as high end, Real Food Daily, Newsroom Cafe and Juliano's Raw will help them at lunch time or for other non fancy meals.
Moose, while it is not in santa monica, Madeleine Bistro is definitely the best upscale Vegan in the Los Angeles area. It has a nice low key decor (dimly lit and dark colors), a great menu and a solid wine list. It is definitely worth the commute. Here is the website: http://madeleinebistro.com/
As far as Inn of the Seventh Ray goes, the food is solid but the Vegan options are extremely limited.
Also, I took my girlfriend to Melisse and had them specially prepare her a Vegan tasting menu...while the regular tasting menu is fantastic and interesting, the vegan prep left a great deal to be desired especially for $80.
Finally, while you're colleagues are in town you should try and make it to Scoops on Heliotrope and Melrose. The owner Tai makes an incredible assortment of Vegan gelato/ice creams that run the gambit wild and wacky to downright delicious. It's out of the way but if you're colleagues are at all like mine and want to stop by Amoeba Records when they come to town its just a short jaunt away.
Valentino - Italian
Qualifies for Higher-End, Santa Monica, and has the best Wine List in L.A. (website says over 2,500 selectons = ??,000 bottles). Now we come to Vegan Friendly, they say at the bottom of their linked menu that they'll be happy to create your favorite dish for you. That being the case, your guests' favorite dishes are all Vegan. My suggestion is to call and confirm that it's No problem: