I've checked wine a lot of times, overseas and within N.America....

Have used both the vertical foam inserts and horizontal cardboard-egg carton style inserts with great success...

Personally I find the horizontal inserts allow for a slightly smaller box, which I often prefer.

However, for the horizontal inserts, I used 1-2 sheets of small bubble wrap on the bottom and top, with one layer between each insert.

For the vertical styrofoam inserts, I wrap each bottle with a sheet of the small bubble erap to prevent excessive movement and shaking of the bottles.

Back in the day, I could also get 18 bottles in a standard carry on (but expanded)... But alas that is only a distant memory now

Good luck!