I am on Remicade for 4 years, had pneumonia this past spring and all that happened was we delayed an infusion until I was symptom free. We delayed the infusion by about 10 days and it was then given after I stopped exhibiting symptoms. That was per GI orders. You should make sure your GI knows and let him or her make the call on whether to delay treatment. Delaying treatment 1-2 weeks while you recover from pneumonia should not be a huge deal.
I had another x ray in June which determined the pneumonia was cleared but I have had a chronic cough ever since which was determined to be due to inflammatory airway disease, bronchiectasis.
BTW I had one of the pneumonia vaccines before I got it and one after (prevlax). They do not prevent all strains of pneumonia especially the viral strains.