I've got jerseys with bits of reflective on the back, around the pockets, but I don't think they achieve much. If it's a vaguely aero drop-bar riding position, you don't actually have a whole lot of back visible when riding along, although admittedly more than you do on a recumbent seat.
I reckon reflective stuff is most effective on the rider's legs, as they're down in the beam of headlights, and moving in a distinctive way. Putting some on the arms makes sense, if only because you stick them out to indicate. Putting it on the bike makes even more sense, because it then doesn't matter what you wear.
I don't think any of it makes you appreciably safer, so wouldn't worry about it.
On a practical level, jersey material tends to be a bit more stretchy than Scotchlite tape, so you'll have to account for that when adding it. You can't just sew a big strip on and expect it not to mess things up. Top edge of the pockets it probably your best bet, and I suspect best results will come from tabs secured by a single seam.
Machine-sewing the jersey material shouldn't be too difficult. Scotchlite on the other hand can be a bit awkward, especially if it's more than one layer thick: Anticipate a bit of experimentation with tension and needle size to get the best results.
Not sure about the iron-on stuff - depends how happy the jersey is with being ironed.
