Hi mfn! And welcome to our All Spain Message Board!
Most bullrings post your "lineup" only a month or two before the bullfight takes place. So for example, if there's a bullfight in May they may post the lineup in April. So, you won't likely find who's on until maybe June for the one you'll likely be attending.
It's really tough finding a schedule online, even for
Las Ventas in Madrid more than a month in advance and even then, sometimes it's not posted.
Here are some websites to check out when time draws near:
http://www.rmaestranzasevilla.es/ http://www.sevilla5.com/monuments/bullring.html http://www.quovadimus.org/spain99/toro-backstage/ Good luck! Saludos, MadridMan