Everyone has their own special mix that they will tell you is the best or only one to use. Truth is that trees are really resilient. They can grow in a really wide range of different soils and your jacaranda will be quite happy in many different soil types too. We generally find a soil that suits our way of looking after bonsai and the local climate but many growers have managed by adapting their care to suit the soil they have instead of the other way round.
I have been growing bonsai for more than 30 years and have hundreds of trees in various stages of development. i use the same mix for all species and all pots except the smallest ones where I sift out some of the largest particles. That works well for me.
If you just have one or 2 bonsai I would advise getting a commercial 'bonsai' potting mix and learning how to manage the tree in that mix. An alternative is to use a 'premium' general potting mix with largish particles.
Making up your own potting soil does have some pitfalls that are not obvious to the beginner until the plants start to die.