Ham is much more useful as a consistent and reliable form of communication overall. And the professionalism of amateur radio ops tends to be much higher.
That said, a CB might be more handy for trail-only situations. More Jeeps have CBs than ham radios.
Really, each offers some advantages but having both would create the most options.
Personally, I only have and use amateur radio in my Jeep.
'16 JKUHR Granite Crystal Metallic. Auto. 4.10s. Alpine.
Gone: '06 XK, '12 JKR, '06 LJ Rubi, '06 WK, '04 TJ, '97 ZJ, '95 YJ