Well,I have used Google Analytics with a gmail account as the primary account to track my site,and I've created a blog at blogspot.com with the the same account.And that blog is used to link to my site,so will google know what I'm doing?
They do know absolutely. However, they will not pay much attention as long as your activity do not pose a serious threat toward them, or defined as "high spam attempt" from their perspective. This is a common that many peoples do create blogs under free solution such as blogger and point links back to the main website. However, if your blog is quality enough then it would be fine but it may not a big impact as it used to be anyway.
If they are related sites too that makes it pretty common to do. Lots of people link their own sister sites to each other. This by itself won't get you penalised.