I always recomend linking your bitmap .tifs. It makes any changes to the placed .tifs in illustrator a breeze (you can just re-link the changed .tif instead of re-doing the whole graphic). Obviously, this only makes sense if you are combining multiple bitmaps in an .ai file.
-Just remember to send the linked .tiffs along with the .ai layout if you send this to another printer!
Do you really trust everyone to save the linked tiffs & not ignore the error message they get if the tiff is missing?
I ask because a couple of years ago I tried it this way & a garment was printed without any of the distressing that would have only shown up with the tiff...
But that was when working with someone in China who notoriously didn't pay attention to details. Ever since, I've always embedded a tiff over vector artwork, but I kind of hate the huge files, especially when I'm using the exact same tiff file in 16+ designs that all need to be emailed & put into work at the same time.
Since I'm not the one sending the files to the printer these days, I don't trust my boss to remember to send the tiff along with the pdf Illustrator artwork anyway, but do you think the average printer would speak up if it was missing, or just continue without it?