Yes the steer manure is fertilizer. I wouldn't fertilize anymore for a while. chemical fertilizers are fine, but just use sparingly. If you over fertilize you'll run more the risk in burning the roots of your roses. I wouldn't worry about the worms and bacteria, they can move out of the way, it's more about the rose plant itself. the chemical fertilizers are more fast acting than the organics. I use both.

By itself, manure is a great soil conditioner and a very poor source of plant nutrients. The fertilizer value of compost can vary all over the place depending on its source. If it has a high carbon to nitrogen ratio, as with shredded barks and woods, it actually may be at least a temporary liability to providing nutrients to your roses. Some composts and manures are fortified with synthetic fertilizers and the label should tell you this.

Almost all the common synthetic rose fertilizers are simply concentrated forms of the same nutrients that are provided by organic fertilizers. Unless you overdose your soil with them, they aren't going to kill the good bacteria or worms. Feeding too much synthetic phosphorous fertilizers may inhibit the symbiotic mychorrizal fungi.

One cup of alfalfa pellets actually contains more than enough of all the essential plant nutrients to feed a rose for a month. The main drawback to feeding with alfalfa, or most organic fertilizers, is the uncertainty in release time. The fertilizer elements are there but they may not be available at the precise times required by your roses. If you want to stick with organics, one reasonable approach would be to apply an inch or two of balanced compost as a mulch each spring, to feed the soil, and then apply alfalfa or cottonseed meal on a monthly basis to ensure that your soil has enough nutrients to feed your plants... and then relax. That's my plan for next year.

Use up the old stuff, why let it go to waste? It won't destroy your garden. The worms and bacteria will survive.