The Manhattan template holds up when añejo replaces rye. Sweet vermouth and bitters have always flattered barrel time, and agave brings a pepper and cooked-fruit note whiskey cannot. The tequila has nowhere to hide here, which is the entire point.
Añejo and reposado both work, but they make different drinks. Añejo leans dried fruit and cocoa against the vermouth; reposado keeps more pepper in the finish. A dry, oak-balanced bottle beats a sweet one either way.