Platinum Equity, the private equity firm that is still slashing away at costs at the San Diego Union-Tribune, is one of two bidders for the Boston Globe invited to on-site meetings, according to the paper, citing unidentified sources. Also invited, the Globe reports, the group led by former Globe digital exec Stephen Taylor; his family sold the Globe to the New York Times Co. (NYSE: NYT) in 1993 for $1.1 billion. Not on the list so far: the other local group that combined the forces of Stephen Pagliuca, a managing director for PE firm Bain Capital and Boston Celtics co-owner, and civic leader and former advertising exec Jack Connors—and, the Globe says, proposed a non-profit model.