Rosa, though Wisteria blooms "look" like grape clusters, they're not
fruit... Fruit's our thing; but we dabble in other plants too. My Japanese Wisteria never did very well, and it was planted out. I guess my focus was on the grape plants next to it?
I've come to believe "anything" can be grown in a pot! But W. sinensis (
Chinese Wisteria) looks to be the most vigorous of "the 3;" how big's your pot? If one
diligently prunes a plant, "Bonsai" for instance, it may be kept within a pot. But with the vigor of this vine, and its capability of covering a pergola in fairly short order, I don't know if the effort would be worthwhile. Diligent pruning; watering; and fertilizing would be a must - and for this vine - I'd hope only temporary.
My concern with "pots" is their vulnerability to freezing. With the roots above ground, the cold penetration is from
all sides. And with the support this vine would need, I can't imagine you dragging the pot to "safety" during every hard freeze? I guess you could bank mulch around its base for insulation, but with all that effort, you might as well plant it in the earth? - which could be tricky if you're on the 3rd floor!
Have fun
! 