The Confraternity of St James published a guide (not currently available) to a route connecting Worcestershire with Bristol. This started in Droitwich, which has given the unfortunate impression that this was a major centre for pilgrims, which it wasn't, despite being a medieval commercial centre because of its salt production. The area around the confluence of the Avon and Severn was however rich in monastic foundations: on the slopes of the Cotswolds were Hailes and Winchcombe; on the Avon were Benedictine Evesham, which grew to become one of the largest and wealthiest in the country, and Pershore, where parts of the abbey are now used as the parish church; at the confluence was Tewkesbury; N on the Severn was Worcester; and S were Deerhurst and Gloucester; to the W were Great and Little Malvern. Any one of these could have been visited by pilgrims.
I suggest a start in the most northerly of these, Worcester, where the cathedral, served by Benedictine monks, housed the relics of Oswald and Wulstan. It has also gained fame in pilgrim circles with the discovery of the so-called Worcester pilgrim, a skeleton of a man buried with pilgrim accessories; see books by Helen Lubin and Katherine Lack. Several of the monastic buildings survive, though the Guesten Hall, the hospitium built for pilgrims in 1320, is only ruins. Nothing survives of the Cistercian nunnery or the 2 friaries in the city. Inside the cathedral, in the S choir aisle, is an effigy of a pilgrim. For some excellent photos of the cathedral, see the 4 pages here.
From Worcester, the Confraternity guide heads to Tewkesbury; the obvious way there is along the river path. However, it's worth making the detour to the 2 Benedictine priories at Great and Little Malvern, both of whose churches survived as the parish church; there are also some remains of the monastic buildings. To the W of the Worcestershire Beacon are a clutch of St James churches: Colwall is partly Norman, but Cradley and the chapel-of-ease at West Malvern are Victorian; there is a well in the churchyard of the latter (indeed, there are many wells in Malvern). E of Little Malvern, Welland has a Victorian rebuild of a medieval church of St James.
The great Benedictine church of Tewkesbury Abbey, like Gt Malvern, survived by becoming the parish church. Some other parts of the monastic buildings survive, notably the abbot's house and the main gateway. In the abbey church is a C14 chapel of St James.
The Confraternity guide next heads to the Cotswolds shrines of Winchcombe and Hailes. Those are dealt with here in the Foss Way page, so we will continue down the river to the next pilgrimage centre, Gloucester. Before there, though, is the church of what was the Benedictine priory of Deerhurst. Though this cell of St Denis was only small, it is one of the finest Saxon churches in the country. A Saxon wall-painting was recently discovered high up on the wall. And not content with having a fine Saxon church, Deerhurst also has another Saxon building: the C11 so-called Odda's Chapel.
Also not to be missed is the small church of St James inland at Stoke Orchard, with its extensive though sadly decayed C12 wall-paintings of the life of St James.
Pilgrims to Gloucester had 2 shrines to head for: the Benedictine abbey, now the cathedral, with that of Edward II, and Augustinian St Oswald's with the eponymous Oswald. Gloucester is particularly rich in monastic remains: there is a second Augustinian priory, Llanthony Secunda, plus both Franciscan and particularly Dominican friaries, the best preserved in the country.
Leave via Lady Well, a holy well venerated by pilgrims, and the S suburb of Quedgeley, where the church of St James is largely C19 but has a C14 tower and S aisle. Follow the canal S to Saul, where St James (photos here) is partly medieval, and then the river Frome to Leonard Stanley, where the church together with a tithe barn is what's left of the Benedictine priory.
The Cotswold Way can be followed S to Dursley, the first of a series of villages along the former Roman road with a church dedicated to St James, and Wotton-under-Edge. S of here, at Kingswood, the gatehouse is all that remains of the Cistercian abbey. On to the other St James churches: Charfield (now in the hands of the Churches Conservation Trust), Tytherington, Westerleigh and Mangotsfield (Iron Acton is James the Less).
From Mangotsfield you can follow the Frome Valley Walkway into the centre of Bristol.