biblatex: Different formatting for citations v. bibliography

\AtBeginBibliography{% 
  \renewcommand*{\mkbibnamefamily}[1]{\textsc{#1}}%
  \renewcommand*{\mkbibnameprefix}[1]{\textsc{#1}}%
}

In addition: The style package option covers both bibstyle and citestyle, so bibstyle=authoryear is superfluous in your example. Also, consider to use the higher-level command \autocite instead of \parencite; this way, you may switch to foonote citations by simply declaring autocite=footnote.

Note: As of March 2016 (biblatex 3.3), you need to change \mkbibnamefamily instead of \mkbibnamelast