I agree with the comments already made about the more negative description of Antiochus in Gower but in contrast with that, he is given more attention in Gower's version before the incest. In the Latin version, no wife is even mentioned. Gower initially describes him in neutral terms, even respectfully and with sympathy when he mourns the loss of his wife. And also his daughter is first mentioned as a source of consolation, at least he has the daughter left when he has no wife, which still seems quite neutral. The Latin is more sympathetic afterwards and even mentions his falling in love and being overcome by love. In Gower, a mention of love in this context would be unacceptable.
There is a structural similarity with Perceval: in both, a parent, having lost their spouse, develops an unhealthy attachment to their child. Perceval's mother maintains her parental role but in the English version, the (very general) theme of child as replacement-spouse is present throughout the narrative because it elaborates on the story of Perceval's father and the similarities/connections with Perceval junior (name, appearance, Arthur's court, fighting his father's enemies. In both cases, it ends with a quest/adventure but Antiochus' daughter, being the passive victim with hardly any agency, is only an indirect cause of Apollonius' adventure rather than herself the hero. (Funnily enough, Chrétien's Perceval meets the Fisher King and Apollonius meets a fisherman and a king.)
When describing Antiochus' sinful desire, Gower mentions wealth as a corrupting influence, making it a general statement and a moral lesson rather than connecting it specifically to Antiochus. His sin goes even further in this version because "such delit he tok therinne, | Him thoghte that it was no sinne" [345-6]. But this might actually make his choice of riddle slightly less baffling.
The Latin Apollonius is more artistic and philosophical, Gower's shifts towards the natural sciences and only plays (and tunes) the harp, no theatrical performance.
Contrasted with the Arthurian romances, the hero's agency is diminished here, especially by (the narrator's repeated mentions of) Fortune. In a way, that is part of the moral. In the storm in the Latin, Neptune (and Triton) are just part of the scenery, an impersonal personification of natural phenomena. In Gower, Neptune is more active, deliberate, aiming specifically at the ship. But Fortune interferes and saves Apollonius from drowning.
The most striking example of cultural translation is the gymnasium scene. The narrator emphasizes the cultural distance by repeatedly mentioning in a short space that it was THEIR custom. While in the Latin, Apollonius is clearly at home in all that, in Gower he is not really part of it, is something of a stranger, just knows a bit of every game. The massage and bath would probably be too exotic, as well as the idea of king's participation.
An interesting difference is in portrayal of Archistrates' daughter. In the Latin, when she falls in love with Apollonius, she responds by taking action that gradually leads to him staying in the palace and teaching her. In Gower, Apollonius himself suggests he would teach her play the harp and the accommodation is the king's idea. And she is made even more passive in the description of her being in love, more strongly reflective of patriarchal society: "wher sche wole or noght, | Sche mot with al hire hertes thoght | To love and to his lawe obeie" [839-41].