Thanks Victor, that isn't the exact syntax, but after much trial and error, I did find a magic combination using dynamic linq.
var Tags = "Visible = true AND Status = Live AND (";
foreach (Guid Tag in selectedTags)
Tags += "Tags.Contains((" + Tag + ")) OR ";
var myCollection = dmm.GetDataItems(iconType).Where(Tags.Substring(0, Tags.Length-4) + ")")
Couple notes...2 sets of parentheses are required for each Tags.Contains. Tags cannot be a string value, it must be a var with guid value appended to it.
edit: changing my answer after finding a solution.