It's certainly beneficial to link to wherever is going to help the user navigate. However, I would be hesitant to put actual links to higher branches in this case because it's likely that the visitor path has already been there and for them to navigate away from the product page would only deter them further to completing your checkout process.
If your current site architecture (read: nav bar in this case) doesn't already link out to the category/subcategory page, then yes, it may help slightly with internal linking "juice", but it will likely be negligible, and you could/should compensate this with things like XML sitemaps anyway.
Another thing to consider would be the opportunity to cross/upsell to other products. It's fairly easy - depending on the CMS you're using - to build in a widget or some kind of functionality to help cross promote products on product pages. I mention this because it's a great alternative to giving people the option to click away from something they probably know they already want, as well as allowing you to increase your price per order by making it easier for them to add "related products" to their shopping cart.
Not knowing your exact situation, I would advise making the internal linking structure whatever is best for the path of the visitor. Make up any internal linking benefit that you think you might be missing by making sure you're XML sitemaps are in order, as well as interlinking wherever necessary in other parts of your site.
Hope that helps!
Related resources:
https://moz.com/blog/results-of-google-experimentation-only-the-first-anchor-text-counts
http://www.screenpages.com/about/articles/ecommerce-navigation