Package variables (and the package instance) are independent to the Template item, meaning a package variable from a Page Template will not be available to a Component Template, since the latter has its own package instance.
If you want to pass variables between Templates (Page -> Component) you can use a
ContextVariable, see also https://code.google.com/p/tridion-practice/wiki/PassContextFromOneComponentRenderToAnother
// in your Page Template
// in your Component Template
var contextBag = (Dictionary<string, object>)engine.PublishingContext.RenderContext.ContextVariables["contextBag"];
I have to add, this is the case for the Modular Templating Framework using DWT TBBs, I'm not a 100% sure this also counts for the Razor Mediator which you are using.