Ive done a similar thing with a signature on a site.
Why don’t you draw your final vine design how you want it to grow to (on a layer). then add key frame by key frame deleting a small bit at a time till you have none left.
select and reverse the frames. when you play it now looks like it is being drawn or growing. ive used this technique loads of times, (Im more are a designer than a scripter ) I find this works and really smooth and well, all tho you need to use a bit of artistic intuition whilst deleting bits.
Yeah thats ok a standard mask, but to get the exact same effect as pseudodigm was after the one on the site http://www.tattoo-world.ru/index.php/ru/ looks like its scripted or a frame by frame mask done on loads of layers it is so smooth, ive used masks a lot, but to get them that smooth. i dont know, gunna have a go