Environmentalists disagree. The picture is complex. I realize that any box, whether bag-in-box or Tetra, is more efficient and economical to ship, warehouse, and shelve at the store. And all the component materials in Tetrapak are individually recyclable (paper, plastic, and aluminum). The problem seems to be in separating them out. From the Toronto Star:
The mass conversion by the LCBO from bottles to Tetra Pak wine is hitting high gear. The idea is that this is environmentally friendly. In fact, these complex cartons are the toughest thing in your Blue Box to recycle and one of the most expensive to process.
Tetra Paks have three main ingredients: paperboard, polyethylene plastic, aluminum foil. To break them down, you need a pulp mill, which soaks them in water, then shreds them. The plastic and aluminum is deposited as a sludge. Little of the paper actually gets recycled, but what does goes into such things as toilet paper. The used Tetras that are recycled make it to Michigan, where there are two plants to process them. But top environmentalists believe most Tetras are still winding up as garbage in Michigan landfill.
Reporter Gordon Stimmell points out that, while bottles are much more easily recycled, they present their own problem. Different colored bottles deposited into recycling bins are too often broken and mixed, making them unsuitable for many uses. Bottle deposits would reduce this problem greatly, but the LCBO has "resisted fiercly" a bottle deposit program.
Clearly bag-in-box packaging doesn't present the same difficulties in separating materials.