Hello OP,
to squat 115 kg should be a matter of weeks for you if your squat is currently at 90 kg x 6. It certainly should not take you longer than 5 weeks. The 2 x bw squat should also be much more of a mid-term goal than long-term. If as an athlete it takes you years to get there, as mutumbo seems to indicate, something went very wrong along the way.
It is btw. impossible to predict how much it takes for you to be able to jump 35. Some never get there. All one can really do is train correctly.
I want to emphasize that time is precious. A goal like this has a decay meter. For most people a large percentage of the progress in vertical happens in a relatively compact time frame. The reason for this is to a degree a psychological one, but age can a play a role as well. Momentum is a largely underestimated factor in training in general. This is why cycling between strength and power phases, between gaining weight and losing weight, between program X and program Y is a huge waste of time and should, if possible, be minimized. A sub-goal like squat 2x should also be dealt with ASAP, not adjourned over and over in favor of some other stuff. Once you are decently strong in the squat and deadlift and can powerclean an adequate amount, you can fine tune stuff with snatch variations and plyometrics. But really, before you are strong, you do not need to worry.
For as long as it works, which differs with individuals, increasing your squat generates the most reliable and easy to get progress in VJ there is. I recommend you to read this book btw., if you are serious about your training. It will do you a ton of good and put some of the stuff you read on forums into perspective:
http://aasgaardco.com/store/store.php?crn=199&rn=413&action=show_detail
