Opps. My original receipt says "This is cool, I'm all in" and that was for the $100. The second receipt say "100 to 1000 I'm in upgrade". So I'm thinking I did it right but my sister when she tried to upgrade hers it only gave her a $100 option when she had clicked on the $1000 dollar upgrade. So she has two receipts for $100. That's what got me to questioning mine.There is not a $900 reserve option so I think you are safe and it just tacked it onto your 100 to bring you to $1000.
I would not worry. You should get a reservation number now.