SO my cat really had uti

I took my cat to another vet and they said she is not diabetic (no sugar in urine) she does not have kidney issues and she is very healthy but has uti again

So he gave her a shot of anti biotic

Does this almost always work? It worked in the past.  I was feeding mine high qality wet food with water mixed in!

Wet food wont cut it for her which is sad because i had my hopes up and now i have all these extra cans she cannot eat

he said she has a reallly thick nice coat and that uti is her only issue she is 8 years old

Stress is a common factor in UTI's. Look into Feliway. It helps calm down stressed out cats.

I am not sure what your question is. Does WHAT always work? Antibiotics to treat a bacterial infection? The answer to that is usually. It depends on which type of bacteria is the cause and which antibiotics were given. A culture and sensitivity test can identify that if the current antibiotics don't work.

I am also confused about the wet food. She was eating that but now won't?

I'm sorry your cat is having this problem.
Curious: why was your cat tested for diabetes? Was she showing symptoms and the tests revealed crystals, but no sugar?
As vBall91 indicated, it depends on what type of crystals were found insofar as whether antibiotics/food usually solve the problem.
I am assuming (a) a urine culture was done and the way of getting the urine was done by a vet, (b) crystals were found and (c) those type of crystals are struvite, versus oxalate.
Antitbiotics + wet food + extra water helps with UTIs; dry food worsens the problem. Yes, prescription food for struvite based crystals is sometimes the only thing that works. And I *hate* saying that, cause a lot of the Rx foods contain a lot of junk and a very little of the drug, methionine. And of course some cats hate Rx wet food. If your vet recommends dry prescription food for a UTI, well (a) I'd insist on wet food and (b) were I you, I'd seriously consider changing vets.
Surgery is usually the only recourse for oxalate crystals, but are relatively uncommon. If bacteria (and no crystals were found) was found in the urine, then antibiotics are all that are indicated (and presumably your vet would have told you this).
What does your vet say about Rx food, or why she has yet another UTI?
Finally molldee has an excellent suggestion: UTIs can be caused by stress. You can try Feliway and increase play time.
Ritz (female) is prone to stress-induced UTIs. Her last UTI was bacteria-based, although before the vet realized it was bacteria, he "threatened" putting Ritz on a prescription diet. I feed raw, extra Turkey Breast when I can buy it cheap (has the most naturally occuring methionine), so feeding Rx food is something I will avoid at all costs.
Good luck, and let us know what happens.