The word to describe when you get an awesome "extra" of something and you didn't realize it or have to pay for it. Basic meaning derived from picking out tropical exotic plants, specifically the tillandsia, a free-growing, self-contained plant. They are often affixed to driftwood. Occasionally an extra one will get stuck to the driftwood and when you purchase it, you got a bonus tillandsia (plant).
Jesse: I like this piece of driftwood.
Hayley: And this one has 4 tillandsias instead of 3! There is one stuck.
Jesse: Bonus Tillandsia!
Hayley: Wow, I found a dollar in the pocket of these thrift store jeans. Bonus Tillandsia!
After having a few glasses of wine and reaching a buzz, this is the effect of gravity versus mind not allowing you to feel any more buzz. The wine begins to taste like juice and you feel no more effects regardless of continued consumption.
hayley: My cheeks felt rosy after those first 2 glasses of wine, but I no longer feel any increasing effects now that I am onto my third.
justin: that is because you have reached your terminal wine velocity.