Is it okay to take this together with green tea and caffeine?
Assuming you have no allergies to the products and can tolerate the caffeine, I wouldn't expect there to be any significant detriment to your health from that mixture. That said, it's generally advisable to dose supplements and meal replacements separately. In your particular case, the following issues arise:
- BCAA absorption might be sub-optimal, as they'll compete for uptake with the proteins you ingest.
- There's some evidence that aspects of the health benefits of green tea are abrogated by co-administration of milk. This effect is attributed specifically to the presence of casein protein, and might reasonably be expected to occur with other types of protein as well. In essence, the protein binds to and forms chemical complexes with some of the salutary constituents of the tea, namely the various phenolic antioxidants. Other studies cast doubt on this purported effect, but it's probably prudent to avoid the possibility altogether.