There's a misunderstanding in the question. There aren't two "bacterial domains". The three domains of life are:

* Bacteria: These are prokaryotes (single-celled organisms without a nucleus).

* Archaea: These are also prokaryotes, but they have unique biochemical characteristics that distinguish them from bacteria.

* Eukarya: These are organisms with a nucleus and other membrane-bound organelles, including plants, animals, fungi, and protists.

So, "bacteria" is a domain itself, not a sub-category within another domain.