Question about Zeller Present Wine rack

Too cheaply made for stacking. For the size ok, but I wouldn't expand - the wood is too thin. . Better to buy a bigger shelf right from the start.

It looks like it's designed more for side by side than on top of each other. But it can certainly be stacked. You would have to stabilise/fix it additionally. But it would probably not fit in an average-sized cellar because of the height.