There are few ways you can say it. בקבוקים של חלב literally means bottles of milk since של means of. But you can also say: בקבוקי חלב which means milk bottles . As for bottle of juice you can also say בקבוק של מיץ and it will have the same meaning like בקבוק מיץ. It's just more common to say בקבוק מיץ.
Yarden, there are bottles that are made for milk, you can call them milk bottles but they are glass. They used to be delivered by a milkman, you can still get delivery in most areas. They are called milk bottles regardless of their contents. They used to have them in the UK too ... example: https://www.monticelloshop.org/020589.html
Thanks. Can't you call one of these a "bottle of milk", too? For exampke, "an empty bottle of milk"? "A bottle of milk filled with water"?
I guess in Israel we used to have dedicated bottles for milk, too, decades ago; and I guess that בקבוקים של חלב and בקבוקי חלב are exactly synonymous, and can be used equally in both cases.
Here's what the bottles looked like https://www.bing.com/images/search?q=welsh+farms+milk+bottle&FORM=HDRSC2&PC=EMMX20
Here's how and why they are back. https://www.ft.com/content/e091c436-3d16-11e8-b9f9-de94fa33a81e
We used to get a lot delivered to the milk box, eggs, seltzer in glass bottles, pretzels. From different companies.
If you ask for a water bottle you'll get an individual plastic bottle. If you ask for a water in a carafe or pitcher that would be the equivalent. If you asked for a carafe or pitcher, unless you had referred to the liquid (Or some place that, say, only serves pitchers of beer or margaritas) usually they'd ask what you wanted inside.
You can refer to it as a bottle of milk if you are asking about the contents. Like in a store that only carries milk bottles or paper or plastic bottles. If you ask if they have any milk or bottles of milk they'll refer you to the section usually regardless of the packaging. But if you are specifically looking for milk bottles say in whole foods or some place that carries all types, you would usually ask for milk in glass bottles. The reason isn't the language itself, it's because most are too young or aren't aware that there is/was a difference. If you ask at a store where they have milk bottles, they'll usually know you aren't referring to milk itself but the bottle. If you asked growing up, and got milk delivery to the milk box in glass bottles and asked where the milk bottles are, if we were out my mom would reply, we're out but I picked up some milk at the WAWA (I think it's like YELLOW in Israel). Milk delivery today I think you can specify what type of bottle you want. At some stores you can still get glass, there's like a 10 cent deposit, encouraging you to bring it back.