Hi T.,
With my son, who was very tenacious and wanted to do things his way when he wanted, we just kept trying. We put his juice in a sippy cup, but his cow's milk in a bottle around age one (right after I stopped nursing him which was another struggle). I remember being frustrated with the fact that he wouldn't take it but kept trying. Our ped's office wants them off the bottle generally by 18 months, but one of the docs there said that there was no real harm until near 2 years old. So, I let him do his thing. Right around 16 months, he just decided that he wanted the cup and not the bottle.
We also have a similar situation with my 11 month old. I am trying to wean him to a sippy cup or bottle so that he will be able to stop nursing soon. He doesn't like either, but I will keep trying. I talked to a lactation consultant, and she mentioned that it was possibly a developmental thing. Once he is ready she said, he will just want to do "older" things.
Good luck!