haproxy match various conditions in use_backend

You don't need to use the word "and" between the two rules. It's implicit.

Source: http://haproxy.1wt.eu/download/1.5/doc/configuration.txt in Section 7.2

Yes, this is the solution:

acl rule1  hdr_dom(host) -i www.uno.es  hdr_dom(host) -i www.one.com
use_backend uno.com if rule1