MecaStack does perform a Vortex Shedding analysis on a guy wire supported stack; however, it is important to note that very few codes go into much depth with regard to vortex shedding on a guy wire supported stacks.  Most of the design codes for stacks are largely based upon self supported (Free standing) stacks, and that same criteria is usually applied to a guy wire supported stack.

It is worth noting that there have been very few instances where guyed stacks actually vibrate, and even in the rare cases where I have personally been involved, the calculations still indicated that there was no problem.  The best advise that I can offer is to avoid the situations which I have seen that led to wind induced vibration:

1)  Top guy wire too far down from top of the stack.  I try to keep the top guy wire as close as reasonably possible to the top of the stack, usually a few feet or couple of meters.  

2)  Structural bridge strand was used in all cases where I have witnessed vibration.  I think it is very stiff and provides little damping.  Bridge strand can be used, but the combination of a guy wire that is far from the top and the use of bridge strand is a dangerous combination. 

Our MecaStack software does consider vortex shedding, but since the codes don't do a great job at addressing this for guy wire supported stacks you should apply good engineering judgement.