No mod you can do to the cylinder will increase accuracy. The only purpose of the cylinder is to supply the moving air which propels the bb. Adding teflon tape to the cylinder head threads might improve fps, but only if there are air leaks. If you absolutely have to squeeze out every drop of fps possible, then check out Silentscope's guide:
http://airsoftsniperforum.com/showthread.php?t=4260
If you already have a good bucking then you shouldn't need to use teflon on your cylinder head or bucking. If you don't have a good bucking, then use a few coats of clear nail polish on the cylinder head nozzle for better contact with the bucking. Teflon tape will simply fall off and jam your gun. For the barrel to bucking connection using ABB rings (anti-blowby (I think)) or trying the bucking to the barrel with dental floss will fix that. teflon tape on the bucking can help but ABB-rings or dental floss will do a better job. And to answer your question, teflon tape can't increase wear.