AusBonsai

I recently riped out a bottle brush tree that has been growing in a crack in the road I drive past. I potted it and it and a shoot grew out of the side. I chopped it above the shoot. What next?

Water it, fertilise it, and love it. That is a good find so let it grow.

Thanks mate. What you see in the pic is the intended front of the tree as I was in traffic while collecting and needed to be quick. Sydney people have no time for urban Yamadori collecting. So I ripped a massive strip of bark down the tree itself. Hopefully this will heal over time. Thank again.

Agree with Watto's advice. The tree needs plenty of growth so you can design something.

What you see in the pic is the intended front of the tree

Not sure how you can pick a front on a tree with just a stump and small shoot. I've always found that they change so much as they grow that a plan has to change to keep up. Now I don't bother to plan until there's enough to do some work on.
You've already found that callistemon have on great advantage for bonsai - they are able to shoot from bare wood. That means you can let them grow freely to gain strength and size then cut back fearlessly to get movement and taper in the trunks and to stimulate more buds to grow new branches.
Good luck with your new callistemon.