In my opinion it will take quite a long time because Appel is a very large company so that the company will think very carefully to accept Bitcoin, so it will be very profitable if Bitcoin can enter the Appel company, and that greatly affects the quality of Bitcoin.
Yes you are right, Apple is a very large company and that's the reason why they will not easily accept or trust someone or even other institution. But I'm hopeful too that bitcoin can.
Apple is itself a big company but if they are adopt bitcoin it will be really an act of honor for both, for bitcoin and for apple. Because bitcoin is also a well known currency as we know people love to buy and sell with bitcoin so they will surely buy the products of apple using bitcoin which will make them in contact with each other so really a great news we should support this news.