Are those Arla returnable milk bottles...  

I find this an interesting....
question because glass versus other packaging materials is at the core of good environmental solutions for packaging. My thoughts on this are that the label recyclable or recycled are not always as relevant as we think. Glass is a good case in point. The material can be recycled yes, but at what energy cost? Considering that the raw materials are over-abundant the main component of glass is the energy it takes to heat the raw materials and form the glass. When recycled the same amount of energy is used to melt the glass and to form it. A recycled plastic on the other hand only requires re-moulding it, which is a small part of the energy consumption and the re-use of a less abundant raw material (oil or gas) The re-use value of glass is quite good. A regular beer bottle seems to be used 8 times in average before it is either broken or surface dammaged to the point where breweries do not want them anymore.
Tetra-pak has re-cycling programs in a large number of countries, but considering the complexity of the lamination, I always wondered what the re-cycled product looks like. I do not think that it is used again in the production of Tetra-pak.
I do not have an answer on your specific question, but I think it is high time to ask these questions and to get inpartial answers.