invasive onion grass
Wild onion is difficult to control, especially in a groundcover bed where no selective herbicide is labelled for use. The seeds and bulblets of wild onion can lie dormant for several years, so even if you get rid of all that are present (and that's almost impossible to do), they likely will resprout.
In a lawn you can use a combination herbicide that contains 2,4-D, MCPP, and dicamba, but this product should not be used around trees and shrubs. You can also spot treat with Roundup, but Roundup would kill lawn grass and vinca that it comes into contact with. If you decide to start over in the infested area, you could spray the entire area with Roundup, wait several weeks for new bulbs to sprout, and spray again.