Hi Cecil - did your recipe tell you to use a two inch piece of ginger, bruise it and take it out after cooking the rhubarb?
My hubby loves anything ginger, so, What i've done in the past is to try all things! Even adding powdered ginger - the result didn't look too good, (cloudy) but at least you could taste the ginger. I usually grate a nice big piece of ginger and add that to the rhubarb (try not to use the fibrous bits) or another way is to use ready crystalised ginger in the jam - about 4oz to every 2lb of Rhubarb - bruise a piece of fresh ginger by giving it a bash with a rolling pin and put it in a bit of muslin and cook with the rhubarb, then stir in the chopped crytalised ginger before potting.
You could even try adding a slosh of ginger liqueur to the mix before potting up, two spring to mind, Domaine de Canton, or the slightly sweeter Kings Ginger Liqueur