In other words when the USCCB declared that standing is the norm for recieveing the Eucharist in the United States, could an individual bishop in his own diocese say that kneeling is the norm for his repective diocese?
I do not think he can; it does not appear that the Church leaves that decision up to individual bishops:
In accordance with the custom of the Church, the faithful may receive communion either kneeling or standing.
One or the other practice is to be chosen according to the norms laid down by the conference of bishops and in view of the various circumstances, above all the arrangement of the churches and the number of the communicants. (1967 -
Eucharisticum Mysterium, n. 34a)
With regard to the manner of going to Communion, the faithful can receive it
either kneeling or standing, in accordance with the norms laid down by the episcopal conference: “When the faithful communicate kneeling, no other sign of reverence towards the Blessed Sacrament is required, since kneeling is itself a sign of adoration. When they receive Communion standing, it is strongly recommended that, coming up in a procession, they should make a sign of reverence before receiving the sacrament. This should be done at the right time and place, so that the order of people going to and from Communion is not disrupted.” (1980 -
Inaestimable Donum, n. 11)
Fideles communicant genuflexi vel stantes, prout Conferentia Episcoporum statuerit. Cum autem stantes communicant, commendatur ut debitam reverentiam, ab iisdem normis statuendam, ante susceptionem Sacramenti faciant. (2002 - IGMR, n. 160)
The
norm for reception of Holy Communion
in the dioceses of the United States is standing. (2002 - GIRM (US), n. 160)
“The faithful should receive Communion
kneeling or standing, as the Conference of Bishops will have determined”, with its acts having received the
recognitio of the Apostolic See. “However, if they receive Communion standing, it is recommended that they give due reverence before the reception of the Sacrament, as set forth in the same norms”. (2004 -
Redemptionis Sacramentum, n. 90)
A bishop may certainly permit both practices,
even though one has been determined as the norm for the diocese by the Conference.
If this posture were regulated (that is, permitted) by an indult, that would be another matter altogether, because indults (if I’m not mistaken) can be declined by each bishop to whom it is offered. So if the
absolute universal posture was kneeling (which it no longer appears to be), and standing was only permitted by means of an indult, a bishop could decide to no longer make use of that indult and require kneeling. However, that is not the case:
no matter what the norm set by the Conference, a person may never be refused Communion based on their posture (standing or kneeling).
Communion in the hand, which
is regulated by indult, is granted to the bishops of a Conference, not to the Conference as a whole. So a bishop could refuse to apply the indult and require Communion to be received on the tongue.