Many United Club (UC) patrons enjoy a glass of India pale ale (IPA).
https://en.wikipedia.org/wiki/India_pale_ale
Cans of "Island IPA" are still complimentary at the GUM UC, so it's not surprising for a UC in IAH to offer at least one brand of complimentary IPA.
A multitude of free IPAs at UCs in IAH or elsewhere would exceed expectations and was likely a temporary promotional introduction to their IPA offerings.