Please let your design team know that it is imperative that they do not design the artwork in CMYK as if they were to print utilizing the Offset Printing Process. The Offset Printing Process allows you to create all colors from the four-process colors (Cyan, Magenta, Yellow, and Black). The Offset Printing Process works because the inks they use are transparent, meaning that if you lay down a square box of yellow ink and then put a matching size square box of cyan over it, you will end up with a beautiful green box.
However, we use the Screen Printing Process when producing your co-branded bottles. We do not use transparent inks. We use the exact opposite, opaque inks. If you do the above process (lay down a square box of yellow ink and then put a matching size square box of cyan over it), you will end up with a square box of cyan. The reason being that the inks are opaque and will not let the underlying ink or bottle color to shine through. It is what makes the bottle printing look so sharp and clean
Your artwork needs to be created with individual PMS colors. Do not expect overlying colors to create new colors or shades. The last color down will be the only color you will see. You can use tints of the PMS in areas where you want a light PMS 185 Red for example, but your artwork would need to be set up that way with the tint.