Funny that the two of us that have actually tried this approach ended up having bad results.
Maybe it says something to the room steward about values, that you "expect special attention just because you have money." I am not saying this is what we were thinking when we gave the pre-tip, I am just trying to get inside thie minds of the room stewards who gave terrible service.
It like this, "hmmm, this guy just hands me $20 and thinks I'm going to be getting out of bed at 3:00 am to get him ice or something for seven days, forget about that, mon. I get my autotip anyway."