WELL BEHAVED kids are not frowned upon at California Grill.
Obnoxious, loud, screaming kids are not APPRECIATED by diners wishing to have a nice meal in a high quality restaurant.
Le Cellier and Coral Reef, being located INSIDE a theme park are much more family friendly. You will be fine in both of these, provided there is something that your kids will eat.
But please, for the sake of the adults who would like to enjoy a nice meal at CA Grill, only take your children if they are
well behaved, and you intend to make sure they mind their manners.
My one experience at CA Grill was so not what I had expected, nor hoped for, due in large part to the cacophony created by the abundance of obnoxious, overtired children who shouldn't have been in that restaurant in the first place, and whose parents seemed to have no idea what a "signature dining" experience was supposed to mean. They were just there to see the fireworks. If your kids cannot stay up until 10pm without completely melting down (and I don't blame them if they are that young...) do everyone a favor and have dinner at Chef Mickey's, where the kids can have as much fun as they want, be loud, and party, and then go out onto the 4th floor observation deck AFTER your dinner and watch the fireworks there.
It's really a shame that CA Grill has become an "attraction" just for families wanting to watch the fireworks...it's supposed to be a fine dining location. I sort of wish they'd get rid of all the windows in there so they could get back to what they do best...FOOD! And it could stop being such a ZOO in there...
Okay, stepping off my soapbox now.
OP: I have a 5 and 3 year old. To be honest with you, I would not take them to CA Grill. There are better options at WDW for kids. The biggest problem with that restaurant is that if your younger kid gets "antsy", or has a complete meltdown, there is nowhere really to take them to escape for a bit (think: Time Out), except out on the roof, which is not ideal. The access to the restaurant is very strictly controlled, and there is no "easy out, easy in"...plus, if you do NOT get a table near the window, it's a rather boring restaurant for kids.