Both raw milk and pasteurized milk will be inoculated with a starter bacterial culture to jump start the process. The difference is which bacteria colonies you will get. In raw milk, you will obtain the natural bacteria and enzymes inherent in the milk from the cow that produced it. You could very well also have an overabundance of the yogurt culture bacteria if they outgrow the natives. With pasteurized milk, the native inhabitants will be killed in the process, and only those used in the culture will be present. Both offer probiotic bacteria, the populations are likely to vary.
I don't know if there is any conclusive evidence to one being more beneficial than another, but raw is always a key word when it comes to health so. (n=1 it)
Raw milk yogurt can be very tricky to handle, because the yogurt bacteria is competing with the natural bacteria in the milk. cultures for Health suggests keeping a "mother" culture with pasteurized or boiled milk for this reason. If you have access to raw milk, and want to make non heated yogurt, there are several room temperature yogurts that you can try.
That being said, the most important item in store bought milk would be the milk quality. Strauss uses mostly grass fed cows, with some silage and legumes, so it should be pretty good milk. Seeing as raw yogurt is almost impossible to buy (most states that allow raw milk do not allow any raw milk products), a grass fed whole milk yogurt is going to be an acceptable alternative.
Nothing to worry about eating pasteurized over raw product. There's a lot of hype around raw dairy, hard to separate the hype from the truth, and the hype comes along with the risk of food-borne illness.
I do believe it kills off the probiotics when it's pasteurized, so I suppose there's not as much (if any) benefit compared to raw dairy. I still eat it because it's what I can afford, but it's more of a treat than something to supplement my diet.