I don't know what order luxuries are listed in, but it is irrelevant. Each luxury is completely fungible, as far as happiness goes.
The *number* of distinct luxuries you have, however, is very important.
For cities without a marketplace, each luxury is worth 1 happy face.
For cities with a marketplace, the first 2 luxuries are worth 1 happy face each, luxuries 3&4 are worth 2 each, 5&6 worth 3 each, and 7&8 are worth 4 happy faces each. That's a total of 20 happy faces for 8 distinct luxuries.
So, when you look at your city, some luxuries (and I have no idea how the game determines what order to print the luxuries in -- and it doesn't matter) will only be providing one happy face while others appear to be providing 2, 3, or 4. It does not matter specifically which luxury is assigned which number of happy faces -- what matters is the toal number of distinct luxuries you have.
HTH,
Arathorn