Lewis seems an obvious choice to be knighted or raised to the peerage. I know that Roald Dahl was denied a peerage or knighthood because of his publicly expressed anti-Jewish views.
Good question. He was actually offered an honour but he declined it. You could find some details on an online biography; try the links from this site (Resources and Links).
There, shining in the sunrise, larger than they had seen him before, shaking his mane (for it had apparently grown again) stood Aslan himself.
"...when a willing victim who had committed no treachery was killed in a traitor's stead, the Table would crack and Death itself would start working backwards."
Who could blame him when the Queen's own husband was offered a knighthood from the Australian government, under the leadership of Tony Abbott, a Monarchist, and a Catholic, which resulted in a change of government and Prime Ministership for Australia, in 2015? Sorry, it is delving into the political, but some of the criticism directed at C.S Lewis is also political, from an Australian point of view. And believe me, I am so gratified that C.S.Lewis at least got the recognition due to him when he got that plaque, on the fiftieth anniversary of his death, in Westminster Abbey.
By the way, C.S.Lewis, I am happy to say, can never be accused of anti-Jewish sentiment. Not only because of his marriage to Joy Davidman but also because the children he hosted in WW2 included Jewish refugees.