Well, you are not working with all the necessary information. That is the great thing about EZ, it doesn't worry you with the fact that the water report isn't complete. Ignorance is Bliss!
You may not need worry about the chloride, but I can tell you that your filter doesn't remove it. If your water has chlorine, the filter might remove that. But its not the same. So there is a need to worry about it.
The Ca and Mg concentrations do not come close to producing the 275 ppm hardness value. I show those concentrations produce 129 ppm (as CaCO3) total hardness. Without the alkalinity, I can't tell what the permanent and temporary hardness are.
Overall, I don't think you need to worry about having a winner...you aren't getting out of the gate. Time to revisit the information with the water company.