B737 Vturb speed is .76/280 for climb and decent and for cruise you use the FMC calculated N1.
I found some captains still use .76 in the cruise if its light to moderate turbulence.
Ooh, yay. One of my favo(u)rite topics.
Per Boeing 737 AFM:
The recommended procedures for flight in severe turbulence are:
1. Air Speed
Target air speed should be approximately 280 KIAS or 0.76 Mach,
whichever is lower. Severe turbulence will cause large and
often rapid variations in indicated air speed. DO NOT CHASE THE
AIR SPEED.
Note that there's no mention of phase of flight, just that the target speed is 280/.76.
Also, check out the airspeed unreliable/turbulence penetration speed in the Performance Handbook or QRH. Those are the same numbers that are in the FMC for Turb N1.