Hi Owo. I've been growing a frangipani in a pot for a few years (I took it as a cutting) and it's gone great just in "regular" premium potting mix. The Scotts one you suggest looks good to me.
As long as the pot has good drainage and your frangipani has leaves on it it should be fine. Mine has been out in very heavy rain over the past few weeks and is happily responding by putting out more leaves.
One thing I always do, though, is put my frangipani under cover when it loses its leaves in winter. When plants have leaves on them they constantly suck water out of the soil through the process of transpiration - the water travels through the plant and evaporates out of the leaves. When plants lose their leaves this process mostly stops, so potting mix can remain wet for a longer time, which can cause rot.
When my leafless frangipani is under cover over winter it still gets a bit of rain drift and I occasionally give it a little splash when watering other things and that seems to work fine.
Other posters here are much more experienced than me, though, so they might be able to give you more detailed advice.
Cheers,
Brad
