While in theory should be fine, it can depend on your system, the manure etc. As it's composted and sounds good I'd think you would be ok, but as always for safety can try in small amounts and always add with bedding.

Here's link from a great site just on this topic.
http://www.redwormcomposting.com/reader-questions/manure-in-a-home-worm-bin/

I don't understand why you want to add sandy soil or commercial composted manure to your worm bin. If you want to get your worms settled, try compost from a compost pile. Or dig into a neighbor's pile of grass clippings that have been tossed over the fence. Dig down and get the black, crumbly stuff from the bottom of the pile. Or go hiking and grab some duff off the ground. Or get some horse manure from a nearby stable, or start your worm bin a couple of weeks before your worms arrive.

After learning how long it takes for greensand to break down in soil and become available to my plants, I began to put it into my worm bin instead. The worms need grit to aid in their digestion so I see it as a good additive. I toss a little a time along with very small amounts of kelp and alfalfa meal.

In regard to adding compost, I highly recommend finding a quality product if that is the route you choose to go. You'll certainly have a superior product in the end in comparison to a bedding comprised of only shredded paper. I use shredded paper along with composted chicken manure as my bedding. Its cost effective and quality at the same time. I also throw in corrugated carboard. For some reason the worms love to leave the cocoons there. The chicken poop can be found for approx $4+ at most nuseries...decent sized bags. Whatever manure you decide, just make sure its composted...you'll be fine.