The electronegativity rating of Ti is 1.8, Fe (iron) is 1.8, and Al is 1.5. All of these are fairly close together so there won't be a whole lot of electron swapping between them. Fe/iron and aluminum parts are typically plated too which further protects them. I don't think it particularly matters what you use, grease or anti seize, so I vote grease because it's a little less messy.

And for what it's worth, carbon fiber tubing and raw aluminum are quite reactive when in direct contact with each other. The early glue together carbon tubed frames had a lot of failed joints due to corrosion. The frame makers learned their lesson and started anodizing the aluminum before bonding and the problems went away.