Semantic Relevancy - Is It Worth It?

[doitnownnn]

I've been reading for a long time about seo, ppc and cpm campaigns.
I wanted to try some out for myself, and the one area I've been having trouble fully grasping
is SEO. Probably because the search engine commpanies don't actually release their exact algorithms,
but let me ask you guys a more specific question about something we do know for sure.

If you do a Google search like this:
~keyword

Yepp, put the squiggly line right before any keyword, you'll see all the bold blue terms
that represent other words with semantic relevancy. Now my question is this...

Is it better to use a semantic term before or after an anchor in a backlink in terms of SEO value?

Thanks!