The problem you have is that your company font is a non-standard font. If you send me something with a non-standard font embedded in it, and my computer doesn't have that font on it, my computer replaces the font it doesn't have with something similar. If you want the slides that you create to look the same everywhere, export them as a PDF. Just understand that any editing done will require a PDF editor instead of Keynote.
In the actual keynote file is text, and notations about how to display that text. The text needs to be "X" color, "Y" size, and "Z" font. If I don't have the font you are using, I can't display it.
The only other way to fix this, is to send a copy of your company font with any Keynote files you create. As long as you own the rights to your company font, you won't be breaking any copyrights by distributing it.