Depending on the context it is either a compliment or an insult. Might mean that your bass lines are intelligently constructed, might be someone telling you that you play too much and/or too much weird ****.
It can mean that you possess great physical skill and proficiency. It can also mean you play like a soulless robot.
Usually, in my opinion, the best musicians have a nice balance of both technicality and musicality. Usually, if someone was to insult you, they would not say "That was so technical". (Being technical is never bad, unless it is not balanced with musicality) They would more likely say "that was unmusical or lacking feel/emotion". Technicality usually refers to the physical aspects of playing such as how fast you can play or how well you can execute phrases. Musicality or "feel" usually refers to other aspects of playing such as dynamic contrast, groove, and other abstract concepts that can be acquired by the tedious repetition of licks and/or scales.
If you're thinking about it now, there's probably a reason. Rather than focusing on the (always tricky) work of assuming somebody else's motives, maybe you could make it something positive by making a change in your approach to music, so that you're happier with how you play? And if you meet them again down the road, you can say, "Hey, don't know if you meant it the way I took it, but thanks - it motivated me to dig into my playing, and I've learned all sorts of neat stuff!" Then kick 'em in the shin and go, "And THAT's for the obfuscation. Yeah, I know technical WORDS, TOO." Apologies, apparently I have an 80 word limit on sunshine and rainbows. It hurt me on the inside.
They can play faster than I can, and I hate them for it. But I have a greater measure of that immeasurable thing called soul. (and, oh yea.... I hate their music)
Gotta laugh....do we go oh gee, miles davis was a bit technical last time i listened, or jimmy Hendrix wasn't so technical at Woodstock and Pavarotti got a bit technical in places.... Ridiculous .......
"Tehnical" can also mean that you understand music well, like knowing theory. Never a bad thing, unless it's from someone who doesn't have the knowledge and wishes they did.