In the unlikely event you've been following this saga . . .

. . . here is an update!

I'm liking:
. . . larger candles instead of tealights, and will try pillars next.
. . . matching (color and shape) sets of bottles in varying heights.
. . . green bottles.
. . . white flowers.
. . . two candle bottles, one bottle vase.

(I apologize for gratuitous use of the ellipsis . . . .)

Got to admit, it's getting better.

I've had some success breaking the bottles. I find the "drip" method word more reliably than the "dip" method.

In each method, you make a score line around the bottom of the bottle with a glass cutter.

In the "dip" method, you keep a pot of boiling water on the stove and a tub of ice water nearby. Alternate hot and cold dips for about 5 seconds each. Do this a few times until the bottom falls off.

In the "drip" method, you keep a kettle of hot water on the stove. Bring the water to a boil, then bring your kettle and bottle to the sink. Slowly pour boiling water along the score line, and then run cold tap water over the score line. Do this a few times until the bottom falls off.

I haven't found a great way to fix uneven breaks. At this point I just have a box of bottles to re-score (about an inch from any break in the glass) and try again.

Here is a small scale prototype. (I only had tea lights available.)