Cemtipede grass is a low fertiliy kind of grass.
Pulled this from NCSU: "High soil pH will cause centipedegrass to turn bright yellow, especially in the spring, due to iron deficiency (iron chlorosis). High phosphorus levels can increase iron chlorosis since it can replace iron in the plant. The use of fertilizers high in phosphorus may contribute to the decline of centipedegrass. Soil test results should be used to correct these problems and to determine fertilizer requirements."
It sounds like the soil lab did not know you had centipede grass and gave you a general guidline to help improve the soil.
You should be using a slow release fertilizer such as an organic fertilizer (sustane, milorganite, etc.)
If your bag says it is mostlye slow release fert you should be ok.

Thank you for researching that for me. I think it would be in my best interest to return this product for something a little more centipede specific. I'm curious though to know whether or not I need to bring my soil phosphorus levels up to a sufficient level? I've read that phosphorus encourages root growth. Or for the grass' sake, should the soil's current sub-sufficient level fine the way it is? Also, I need to do some weeding. My new plan is to obtain some slow release weed and feed fertilizer. After the application, how soon is too soon to spot spray weeds still lurking? Or should I speed zone/ amine 4 the entire lawn before fertilizer app? Thanks again. I would have hated to produce community's most yellow lawn!

You still need a new plan. The problem is you have it baked into your mind that you need fertilizer. With centipede, if that is what you have, you need to do things to worsen the fertility of the soil. Centipede thrives in depleted, acidic soil. No fertilizer is needed, ever.

Rather than getting anything with fertilizer in it, just start spot spraying the weeds before they get out of control.

The other possibility is that you have a St Augustine lawn. Both grasses look similar and would be described similarly to the average homeowner. St Augustine does need fertilizer and is a little persnickety about weed control. It would help if you cut a few or the runners across the surface, take them into a really good nursery, and ask the question, "Is this centipede or St Augustine?" You might try that at several nurseries. If any of them tell you it is centipede and then try to sell you fertilizer, RUN AWAY!