Hi. If your inner pages are in a way nested from your main page, the PR from the main page will flow through them for sure. Your main target will be to get a better PR on your main. If you have time and resources, you can try to get links to your inner webpages as well.
it is just like what you did on your homepage to get PR every page is individual in google's eye. You want to get PR for your inner page, work out some link building on the inner page itself
As lifeplayer said, use inbound links to target your inner pages rather than just your homepage. Each of your sites pages should be viewed as in need of independant SEO.
I agree with Jonah-fish and life player, this is a very common mistake that most of the "SEO Experts" make, blindly back linking the home page and forgetting about other important pages of your website.
Increase the quality link or back link of inner page. submit your inner page link into directory, bookmarking, article, also do link exchange of your inner page.
Indeed inner pages are equally important for strengthening the overall reputation of your website. But, PR is certainly not an important metric. Its better to shift your focus on other factors like traffic, conversion, ROI.