epigenetic vs. environmental factors
If I understand you correctly what you are saying is


  There is envrionmental variance and epigenetic variance underlying the phenotypic variance. There can even be a covariance between the envrionment and epigenetics.


Yes, this is true. You might want to have a look at this intro post to quantitative genetics.

Note, there are several definitions of epigenetics. Epigenetic effects are some kind of factors that affect phenotypic variance and that are external to the DNA sequence. Often we think of modification directly on the nucleotides on on the histones (such as a methylation on the histon tail) but we sometimes also extend this context to include all the stuff that is the in the zygote or sometimes even further. In its broadest sense, the term "epigenetics" would be a synonym of "environment".