"Bridal wear" is a category of clothing. It's the kind of clothing that people wear at weddings.
You use the phrase "___ wear" when speaking or writing about a category of clothing. For example:
Sales of sportswear have fallen by 10% over the last three years.
Here are some categories of clothing that can be described as "___ wear":
- formal wear / formalwear
- bridal wear
- casual wear
You usually only use "___ wear" when talking about clothing as an industry or a product. It would be strange to comment about a friend or coworker's "casual wear".