I had this problem with dd2. I breastfed dd1 unitl she was 1 year old, but she would also take the bottle form 2 months old, this is what helped make it such a good experience. I could feed herself myself or give her the bottle, 90% of the time I fed her myself but it just took the pressure off me.
Well, expected something similar wtih dd2 and how wrong I could be. Tried a bottle at about 6 weeks, plan was to do a similar thing, probably feed her mostly myself but wanted the option of her having a bottle to take the pressure off. But there was no way that she would take, over a period of a few months I tried every type of teat,cup etc and still no luck. Went out for a entire day and left her with my Mum, we thought that would work but it didnt, she didnt have any milk from 9 to 5 and didnt even seem that bothered.
I then totally gave up, as soon as she seen a bottle she was getting stressed, I was getting stressed and it just wasnt working. Left it for about 1 month and then just tried a bottle and couldnt believe it, she took it no problem.
I know of so many mum and babes that seem to go through this problem, out of 8 of us that breastfed, this happened to at least 3 of us.