You can just add your CATextLayer to UIScrollView and get scrolling for free. Set scrollview's frame as needed and contentSize as your CATextLayer frame and add it to scroll's layer, something like this (not actually working code):
UIScrollView* scroll = [[UIScrollView alloc] initWithFrame:CGRectMake(0,0,100,100)];
CATextLayer* layer = [CATextLayer layer];
//layer init code goes here
scroll.contentSize = CGSizeMake(1000,1000);//or your actual text layer size
[scroll.layer addSublayer:layer];
and you are done! Don't forget to add scroll as your view subview.