While I agree that common sense dictates that you should probably not wear a robe or pajamas in the lounge, the information sheet that I was given on my last CL stay said the following: "When visiting the lounge, may we suggest footwear and cover-ups for swim wear. We ask that an adult accompany guests below the age of 10. If you plan to partake in our wine, beer, or cordials, please be prepared to present appropriate photo identification."
As it doesn't specifically say that you can't wear a robe or pajamas, I am not sure that Disboarders can arbitrarily say what the rules are for dress code in the club lounge.