Across 1,862 ranked games on patch 16.21 in Master and above, Yunara mains win 52.5% of their games in the bot lane.
Their most common build appears in 58.4% of those games and wins 55.1% of its 1,087 games.
It starts 
two Health Potions and 
Doran's Bow, completes 
Yun Tal Wildarrows, 
Runaan's Hurricane, 
Infinity Edge and 
Lord Dominik's Regards in that order, and takes 
Gluttonous Greaves.
Two other builds are played often enough in the bot lane to be measured on their own.
In the bot lane, Yunara mains fare best against 
Smolder (won 81.8% of 11 games), 
Samira (won 76.9% of 13 games) and 
Ashe (won 73.3% of 15 games).
Their hardest matchups, the champions that counter Yunara, are 
Aphelios (won 41.9% of 93 games), 
Jhin (won 46.7% of 107 games) and 
Caitlyn (won 45.2% of 62 games).