I used to use it a lot Rich but on it's own and not with groundbait as that takes away some of it's effectiveness
Had some amazing sessions with it in the past for the fish you mention (and Roach/Rudd etc) and mainly on the float with worm tipped with corn as bait.
Although PC is good I found Parakeet/Cockatoo mix better as it contains maize flakes which when boiled release a lovely creamy slick into the water.
Soak the seeds in boiling water in a closed bucket for 24 hours and add boiling water top up as the seeds swell.
Boil for 30 mins or longer if seeds seem hard and then put back into the closed bucket with the water the seeds are in .
Leave for a day or so and the seeds ferment and release their sugars - this is added attractant.
Carpers tend to use it as an inexpensive bulk feed. Mixing it with groundbait would seem to rather defeat the object, though there's nothing to stop you doing it. I'd also be wary of diluting the effectiveness of both things by mixing. Both tench and bream (and other smaller species) will respond to various particle mixes, but much depends on the water concerned.
I'm not actually that keen on Pigeon Conditioner as a mix. They do vary, but most seem to have a few different seeds that I'd rather not have in a mix. These days, I tend to use stewed wheat as a bulk particle. It's cheap, takes no real preparation and can be easily done (a flash over with boiling water the night before use and then allowed to sit in the water is enough) in any quantity. I've used it with success for tench, barbel, carp and roach. From a pint of it loosefed on a small pond to bucketfuls spodded into a gravel pit. It's so inexpensive that I'll happily feed it just to clear, or keep clear, patches of weed.