I would go more towards the second one being jonellus, as mentioned above, they are shorter faced and are always on my Ceanothus, but I've never seen the longer faced hortorum on this plant. Secondly the size of the bee against the flower suggest jonellus which is always smaller than hortorum by some margin.
Many hortorum are only just at the start of their nesting cycle, whereas jonellus has been out for a number of weeks and nests are well established. Also, bear in mind that jonellus is NOT tied to heathland despite the pointless/misleading 'English' name.
I have a friend who has spent many years working on Bumblebees and has informed me in the past that he has studied nests of jonellus on Romney Marsh (nowhere near any significant heathland), the Somerset Levels and, more importantly Salisbury Plain the largest area of chalk grassland in southern England. He's also mentioned in the past seeing male jonellus in the first week of May as a testament to their early season while hortorum queens often only emerge in late April to coincide with the first flush of White Dead-nettle flowers which seem to be quite an important early forage resource when other plants with long flower tubes are in relatively short supply.
Hope this helps.