In the Camber and post-Camber books, only the clergy normally took both the Bread and the Wine; the Michaeline custom of everyone taking both was remarked upon as being unusual, and shocking to the ex-priest Cinhil.
In "The Priesting of Arilan" the fact that as a newly-ordained priest, Denys would take both the Bread and the Wine was a major issue.
HOWEVER, I have just re-read "In the King's Service" and "Childe Morgan" and in both there are numerous references to the laity taking the Wine. As Arilan was ordained after ITKS and CM, this seems to be a contradiction.
In our own world, communion in both kinds was a major liturgical change in the Church of England after it broke with Rome under Henry VIII; one of the Anglican XXXIX Articles says "the Cup of the Lord is not to be denied to the laity." In the Roman Church, the laity took the Bread only at least until Vatican II, and I am told that in some places even now that is the observance.