Currently I have worked a particular clients website to the first page of Google with their chosen key phrase. This has been done with what I believe quality on page seo and the commissioning of an individual who does my link building. The problem I have is secondary pages. The pages will be fully optimised for their key phrases, likewise content focused towards that particular niche. Nevertheless I am unclear as to whether I should go ahead and commission my back links for none home page. I would be grateful for any tips or recommendations to aid this problem. Thanks.
Actually, links to inner pages are VERY valuable. Sites with almost all of their inbound links pointing to their home page will never be seen as authoritative. Sites with links from many sites to many pages on their site are seen as authoritative. Also it's a LOT easier to get 20 pages to each rank for a different keyword phrase than it is to get a single home page to rank for 20 different keyword phrases. So yes... build links to inner pages as well.
You need to deep linking for inner pages of your site using your keyword specific pages as anchor text while building links.