Take an s.g. now and then tomorrow. If they haven't changed at all, then you'll have to repitch yeast. But, just because it's not obvious, doesn't mean it's not happening. I have an apple wine that is barely showing any airlock activity at all. However, there are tiny bubbles on the surface and some lees are forming, so I'm just waiting and waiting.
But if the fermentation is truly dead, the best thing to do is to make a yeast starter. Using the same yeast type that you've already used, rehydrate and then add a tiny bit of the must to it. Then a couple hours later, a little more. Do this for a day or so, until the yeast is still fermenting the must you add. Then add that yeast to your must. Really baby those starters because you don't want them to stall too!
I'm sure that the orange juice is what's causing the issues in that one. That's alot of acid to add and I bet the yeast are struggling. (I had similar issues with hard lemonade). As for the tea, I have no idea- but that's quite a bit of tannin. Maybe the yeast don't like it in that recipe?
Anyway, that's my best advice.