There is good news and bad news - first the bad news:According to this USDA Plant Profile Map, Muhlenbergia capillaris (Gulf muhly) is not shown on this USDA Plant Profile Map as being native to any state closer to California than East Texas. As you may know, The Lady Bird Johnson Wildflower Center, home of Mr. Smarty Plants, recommends the use of plants native not only to North America but also to the area in which that plant is to be grown because of plant needs for climate, water and soils. So, it would be almost impossible for us to say if it would do well there.
However, Californians seem to be game at trying just about any plant, so if you are also game, we suggest you first follow this plant link Muhlenbergia capillaris (Gulf muhly) to our webpage on the plant and compare your climate and growing conditions with those listed on that page, especially the Growing Conditions:
Water Use: High
Light Requirement: Sun
Soil Moisture: Moist
CaCO3 Tolerance: Low
Soil Description: Sandy soils. Sandy, Sandy Loam
Conditions Comments: In the fall, gulf muhly creates a stunning pink to lavender floral display. It functions well in meadow gardens and as a general garden plant."
Then, read this article from the Master Gardeners of Marin Garden CA on Muhlenbergia in California. Remember, we can make no guarantees, nor do we have information on whether it might be invasive in California, so you need to check on that.