Good relations between an airline in ATC never hurted anyone and makes life easier. A TV for the rest room or a few free tickets for the raffle for the Christmas party, where is the problem ? This ain't personal to one person , it showing appreciation to a group. Other groups at airports receive the same.
Getting priority over another one ? too complicated and will bite you back as a controller.As said before nobody does this. The percieve feeling of being by-passed as a pilot is not because of you, but because it makes our life eeasier. Type of a/c and company policy ( e.g. fast climbs and descents) may alter sequence depending on a lot of factors .But giving systematically year long priority to one airline over another ? no way. Too complicated.