I can't find any solid info, but I did find a Wilamette & Pacific retirement letter in PDF form that references the Bailey branch, so I assume all or part of it was leased to W&P and is thus part of the W&P/P&W Oregon empire. I can't find any references to the branch on the official website though.
AFAIK- It's still in use. And it shows on the route map at the G&W/PWRR web site. Portland & Western RR System map Route 13- P&W RR Bailey District. Boxcab E50