I'm assuming you are talking about flight dispatch, the international definition of the term as opposed to the UK variation which is ramp dispatch; the two are not the same.
In any OCC I've come across, the reporting structure for crew control, ops control and flight dispatch tends to be ultimately through the same person. Either an Ops manager, an Ops director or ultimately a COO. You might have a supervisor who you would directly report to but the person who manages the department will make the ultimate decisions on hiring, promoting etc.
My point is this; if you have a flight dispatch licence and you are presented with an opportunity to work in an airline crew control position, then it is highly likely that your boss will be the same person who is responsible for the flight dispatchers. Do a good job as a crew controller and you are in a good position to promote yourself as a candidate for flight dispatch. 99% of the time they share the same office anway so everyone would already know you.
I've taken many ex-crew controllers into flt dispatch and it works just fine. It is also easier to replace crew controllers than flt dispatchers in my experience so I'll always promote from within when I can. It is also common in many companies that have unions
to insist on promotion from within.
It really depends on the airline and the pay structure. Crew control is usually a step up from the ramp and a step up is a step up, whichever way you look at it.
Good luck.
D.O.G