Yes the Swiffer Wet Jet is fine for use on Vinyl Plank Floors.
I use a Swiffer Wet Jet in between mopping of the Vinyl Plan floors I have and it's always been just fine.
I mop the floor with vinegar and water every 3 days and then on the other days I will use the Swiffer Wet Jet for a quick cleaning of the Vinyl Plank Floor.
I also use some Murphy's Oil Soap in my mop water sometimes as well to keep the Vinyl Plank Floors looking good.
But yes a Swiffer Wet Jet is perfectly okay to clean your Vinyl Plank Floors with.