Answer:
Both honesty and loyalty are two very important values for a person's social ties with third parties. Thus, honesty implies a vocation to behave according to the truth and without deceiving others, while loyalty implies the behavior by which the person will not betray or stop supporting another, or a particular cause.
Now, when comparing, I believe that honesty is a more important value. This is so because honesty implies a general behavioral parameter, that is, of the individual towards the whole of society, while loyalty is with respect to a few people. In this way, honesty tends much more to the common good than loyalty.