The added detail is very helpful Bob.
FWIW, I’m fairly certain that the casino coding of the charge is what makes the difference here (not the credit card used). Generally speaking, it would be to the casino’s advantage to code the transaction as a cash advance, since it would avoid merchant fees otherwise incurred on purchase transactions. (This is why there’s a 3% fee typically levied against the cardholder on cash advance transactions.)
I can only assume that, at casinos such as Atlantis, card charges to repay credit lines is a relatively infrequent activity and they’ve opted to keep things “simple” (my guess is that such treatment is contrary to their merchant agreement).
This may very well be true elsewhere … perhaps even LV. Assuming they don’t make you take a separate cash advance through the standard cashier terminal mechanism, I suppose a direct repayment transaction might be coded as a purchase. Guess I’m getting a little too “programmed” to anticipate the worst 
—In vpF…@…com, <bobappic@…> wrote :
A few comments re: the thread re: paying markers off with credit cards:
• Although I’ve been using markers for years, I only thought to ask about paying with a credit card 2 visits ago. Both trips were to Reno, and I paid off markers at the Atlantis and Peppermill with no problem, up to $4K
• I was not charged the 3% you might expect, and I certainly wasn’t charged as if it were a cash advance (those fees are horrendous, which is why I never even consider cash advances on my credit card)
• I have a Comenity Total Rewards Visa card (sponsored by Caesar’s Entertainment) that I use for those casino transactions. I’m sure that the type of card makes no difference to the casino, but I can’t speak to how other credit card companies would respond to such transactions (a concern raised in an earlier post). I’ve had no problems with fees nor reporting to credit bureaus.
I’ll be curious to hear how this works for others who actually try it in other casinos.
Bob in San Antonio