I have a PP(or Velvet) plant/vine. It is 13" tall and has 13 leaves. I would like to cut it down to 6" and root it in my Beta's (fish) bowl (the plant is supposedly non-toxic)or should I just cut it and put in the soil?

I have a Tradescantia Zebrina (Wandering Jew)(found on ground in a parking lot two weeks ago, no monetary risk) doing fine in the bowl with 3 one inch roots, should I plant now or leave it in?