Rock and Roll
Rhythm and Blues
Country and Western
Bubble & Squeak.
There’s the traditional Christmas drink, Tom and Jerry. Which of course lead to not one but two cartoon duos.
Town and Country, Missouri.
State of Rhode Island and Providence Plantations
A couple of supermarket chains.
Shop and save, and Stop and shop.
and
Here’s an oldie but goodie.
Coat and tails, for formal attire.
Hunt and peck, for a keyboard style
Black and tan, a paramilitary force
Hue and cry, a protest
William and Mary, a university
Cat and mouse, a tactical competition
Dr. Jekyl and Mr. Hyde, the same person
P’s and Q’s, what you mind
Over and under, a shotgun
How 'bout two for the price of one?
Ringling Bros. and Barnum & Bailey Circus
Nope.
While in theory you could have a Spanish lastname with a “y”, it is a highly uncommon way to compound two previously-independent lastnames. In every single one of your examples the “y” is there to mark the separation between two lastnames. Nowadays both that “y” and the “de” have fallen into disuse (they have stayed in some specific examples, everybody refers to Ortega y Gasset as Ortega y Gasset because Ortega Gasset sounds like you’re gagging), but for several centuries the long form of somebody’s name would be Firstnames de Firstlastname y Secondlastname.
Romeo y Julieta cigars
We could narrow this down to cases where the conjunction is integral to the name of a unitary thing, as opposed to describing two separate things that are generally considered together. One can visit Tobago without Trinidad, but cannot go to Truth but not Consequences. One can eat bangers without mash, but not bubble without squeak.
Interesting that we now have just Rock, and just Country.
Will R&B ever become just R? Doubtful – people rarely use the full phrase (rhythm and blues), especially since the phrase has evolved to describe a kind of music that contains no special rhythmic qualities, and almost never blues chord progressions (but admittedly sometimes retains traces of blues lyrical themes).
Arts and Letters, finished second in the 1969 Kentucky Derby.
Houseing and Urban Development, a cabinet post.
Darmok and Jalad at Tenagra.
A few games come to mind, like
Snakes and Ladders (Chutes and Ladders, in the USA)
Hide and Seek
Truth or Dare
I call them sprinkles, but I know other people call them hundreds and thousands.
Then I was thinking “but maybe hundreds and thousands aren’t really a singular thing. After all, there are a whole bunch of tiny sprinkles in that jar.” But I think the singular would be “a hundred and thousand” if you had to talk about just one.