That story is from 2 days ago before it passed and is no longer a relevant point.
The issue was that 4 republican senators stalled the bill to try to weaken unemployment benefits. Sanders made a counter-threat to stall the bill if they didn't withdraw their objections, to prevent the Senate from giving in to their objections.
Sanders objected to an amendment proposed on Wednesday afternoon by Senators Ben Sasse (R., Neb.), Lindsey Graham (R., S.C.), and Tim Scott (R., S.C.) that would cap unemployment benefits at a worker’s previous salary level.
Sanders, AOC Threaten Delays on $2 Trillion Economic Stimulus - National Review
"Unless Republican Senators drop their objections to the coronavirus legislation, I am prepared to put a hold on this bill until stronger conditions are imposed on the $500 billion corporate welfare fund," Sanders declared, shortly after Sens. Lindsey Graham (SC), Tim Scott (SC), and Ben Sasse (NE) threatened to delay the Senate bill.
Sanders Threatens to Demand Stronger Conditions on $500 Billion 'Corporate Welfare Fund' If GOP Moves to Reduce Benefits for Laid Off Workers - Common Dreams
In the end, a compromise was reached where the Republicans were allowed to propose an amendment to weaken unemployment benefits, it was voted down, and then the bill was passed unanimously.
They were given a vote on an amendment to pare back the unemployment benefits but the measure failed on the Senate floor Wednesday shortly before the bill's final passage.
Senate Passes $2 Trillion Coronavirus Relief Package - NPR
At this point, the bill has passed the Senate and, assuming the House approves it as is (which they are expected to), the Senate has completed its role in its passage.