Boil wine, orange juice, zest, and 100g sugar in a pan over medium heat.
Simmer until the liquid reduces by two-thirds and cool.
Melt the chocolate in a bowl over a pan of simmering water.
Whisk the wine syrup into the melted chocolate.
Stir the egg yolks into the chocolate mixture.
Heat milk, cream, and 50g sugar to scalding point without boiling.
Whisk the chocolate mixture into the hot milk and cream.
Stir in butter, pour into eight ramekins, and chill for at least two hours.
Boil water and 150g sugar for 15 minutes to create a golden-brown caramel.
Remove caramel from heat and cool slightly.
Add orange segments to the lukewarm caramel.
Fold cream and mascarpone into the caramel mixture.
Spoon a quenelle of the mascarpone sauce onto each chocolate pot to serve.