I am remodeling my bath and will have a 1/2" subfloor installed over existing hardwood floor (vinyl will be installed later). Will I need to bring the height of the closet flange up higher? If so, how high should it be above the new subfloor? Is this something that's easily done after the new subflooring is in? Does it require removal of the old flange and a new one installed? Thanks in advance.

I am remodeling my bath and will have a 1/2" subfloor installed over existing hardwood floor (vinyl will be installed later). Will I need to bring the height of the closet flange up higher? If so, how high should it be above the new subfloor? Is this something that's easily done after the new subflooring is in? Does it require removal of the old flange and a new one installed? Thanks in advance.

You will extend the flange up enough to mount on top of the finished floor.
They make flange extenders for that,(see image) and here's a link to check them out; http://www.quickfixplumbingproducts.com/closet%20flange%20extenders.htm
Good luck, Tom