Q: Now that my garlic plant has this beautiful bloom will it have a garlic bulb or onion to harvest or do I just leave it?
A: By the time the plant flowers, garlic may be a little past optimum harvest time. Go ahead and dig the bulbs now. It is fine to use them for cooking.
When the flower stems first emerge from the ground is a better time to harvest.
By the way, the things you see in the garlic “flower” are not seeds but bulbils. They can be separated and planted as you would seed.