Iāve used Rooibos tea in my tanks in the past before though not your particular brand but as long as itās 100% natural, organic and no additives at all then should be ok to use, would use sparingly at first just in case and if you see any effects at all on livestock, do an immediate large water change but thatās only if you see any effect after adding that brand of Rooibos tea.
And as fo using both IAL and Rooibos, yep should be good as Iāve done this as well, both of these have good antitoxins for your livestock and naturally darkens the water column and can look fantastic.
Let us know how you get on and of course some pics if you can of what the water looks like after adding the Rooibos and IAL would be great