"The wine bottle is empty."
Translation:בקבוק היין ריק.
AniOhevYayin (presumably an expert on wine bottles and their contents) is correct in saying that the article (used as a copula) is needed where both parts of the sentence are nouns, and not needed if the second part is just an adjective (or adjectival phrase).
But there are exceptions when the subject noun phrase is more complicated, or where there would be an ambiguity - then you would, in fact, use the article before the adjective.
For example, if you wanted to tell someone that:
"A red-wine bottle is green"
i.e. that a bottle manufactured for red wine is made of green glass, then you would say in Hebrew:
בקבוק יין אדום הוא ירוק.
Here, if you omitted the article, then the listener might have trouble grasping the sentence immediately - it might sound like a nonsense phrase about red-green wine (in a bottle), or about a red-green bottle (of wine).