Your reply is definitely above and beyond what my post deserved. I'm impressed with the engaged community in the IHG forum. Thank you.

This does explain why we didn't get the 20% off drinks over dinner. I don't care as the meal itself did exceed our expectations for the hotel and the price we paid. I actually quite liked the hotel overall. I've stayed hundreds of times at Le Meridien around the corner and will continue to do so but I didn't see anything at the CP that would put me off if I was an IHG elite with lounge access and I wanted to be around Silom. The price of drinks there was also a little lower than I was expecting at a branded hotel in Bangkok. You are correct about ordering. We've lived in SE Asia for 12 years and Thailand for the last two years and evidently still make rookie mistakes on occasion when our guard is down. My excuse is that my partner ordered the wine and cocktails and the water was an afterthought. Most restaurants we go to - even decent ones - will just bring you a plastic bottle of chilled and filtered Thai branded water so we weren't on the lookout for upsells. In terms of stings, though, it does not come close to the time I was victim of the classic tuktuk jewellery shop scam on my second trip here about 25 years ago.