Conversation so far:
What business was Newsom involved in?
Newsom and his investors created the company PlumpJack Associates L.P.
What did this company do?
the group started the PlumpJack Winery with the financial help of his family friend Gordon Getty.
Was the winery successful?
According to Getty, later business investments were because of "the success of the first..

Question: Was he involved in other businesses?
Self-contained rewrite: Was Gavin Newson involved in other business besides PlumpJack Winery?