Resumé – how to include grant awarded to my undergraduate project but is part of a bigger grant?
My immediate reaction is that if you weren't involved in the writing of the grant, you aren't responsible for the awarding of the grant; rather, you were hired to a position that happened to be funded by that grant. Therefore it would be misleading/unethical to list the grant on your CV/resumé, but you can and should list this position, along with your responsibilities, skills you learned, any results or publications, etc.

(Incidentally, it would be a terrible idea to list the full amount of your PI's grant. Not only is it unethical, but it would look laughable that an undergraduate had been awarded a six- or seven- or eight-figure grant. The result would be that the committee would view your entire application with suspicion.)