As Luis and also GregT have noted, the great wineries in Haro are all huddled closely together, with La Rioja Alta almost directly across the tiny little street from Lopez de Heredia, and Muga just a short walk down. Btw, the locals all seem to refer to Lopez de Heredia as “Vina Tondonia”.
And if you make it up to San Sebastian, be certain to go to Rekondo. My wife and I drank the '68 Tondonia Gran Reserva (200 euros) and the '81 Tondonia GR (80 or 100 euros). You’re not likely to find better prices on wines in general and Rioja in particular anywhere. Be sure to ask for a tour of the cellar, and be blown away. Here are a couple of articles of interest (and I link to Suckling site regrettably, but it is a nice write-up by someone else):
Worth watching Bigas Luna’s hilarious satire of Spanish machismo, Jamón Jamón, starring Javier Bardem and a very young, often very naked Penelope Cruz. Oh yeah… it features those bulls quite prominently, in particular a scene where Penelope takes cover from the rain under … ah well, you’ll see. The symbolism is not subtle, but it’s effective and funny and ultimately … weirdly moving.
So, um, underwear factories, naked bullfighting, breasts that smell like tortilla de patata and jamon, naked Penelope, a fight to the death with some grotty looking hams, tragedy, redemption, naked Penelope…
I tasted at Mauro and Pesquera in 2001 and was able to speak with them in English. Is that a given at major wineries? In Madrid and Barcelona, I found a lot of people who did not speak English and felt pretty helpless since I don’t speak Spanish.
Pretty much in my experience (e.g., Freixenet, Torres, CVNE, Contino, Riscal, La Rioja Alta, etc.). Even though my Spanish is ok, in these big producers, an English speaker will automatically be assigned if they know you speak English - amusingly, when I had my private tour of La Rioja Alta, the PR Directress (who saw me a few days earlier at Arzak) advised the wine maker/technical diector that he could conduct his lecture in Spanish as my wife and I could understand. Julio looked visibly relieved when Gabriela told him that, and promptly switched to Spanish. I had to ask him to speak slowly when he came to technical stuff though.
In short, you should be fine during visits to the bigger producers.
As Greg T. said, do visit Protos. Carlos Villar Bada, who I think is still director general, speaks English perfectly, so I’m sure he has provided for English speaking guides thereat.