Do lilies benefit from a handful of manure when planted in pots?

I wouldn't put animal manure in any pots, Jonathan, it is much too strong.
The flower power of the potted bulbs this year will reflect on how well they were looked after last year. The flowers are already stored within the bulb and it was last years feeding that will make them big and strong for this year. For lilies I would plant them in a good potting compost and then give them additional feed, such as liquid tomato feed, as the summer goes on.
I hope that your garden looks as good this year as it did when the picture was taken.

Thanks for that information Bulbaholic. Oops! I'll have to go and change what I did this morning. I put some muck in. What would you say is a good 'potting compost'? I was thinking of using John Innes no 2 and multipurpose, mixed half and half. Am I on the right track do you think? I've lifted them and had a look at these bulbs, and they are about double the size of when I originally planted them about two and a half years ago, and no sign of disease or slug damage. So I am expecting another good display from them this year. 'Stargazer' is superb. Of all the lilies I have ever grown it is definiitely one of the best, so I keep it going every year if I can.

By the look of your picture, Jonathan, just carry on doing what you usually do, you've got it right so far! Yes, a mix of JI#2 ans multipurpose sounds good to me.

I usually pop a few slow release pellets in with the compost when i plant them up. then feed later on in the season.

Yes, that's what I'm going for. Some slow release, and then some tomato feed when in flower.