TAF winds are given as true winds.
ATIS winds are magnetic,
Tower gives you magnetic winds as well.
Enroute winds are true.
Basically, all winds are true, unless you need the wind for take off or landing and there you need magnetic, because the runway heading is magnetic.
Magnetic heading: mag compass doesn't work at high latitudes, INS/IRS systems don't align above certain latitudes north and south. It's published where to switch modes.